So, for my latest game, I've been thinking about playing a character who used to be a tattoo artist. I tried to find a picture for his wife, and I found one that I really like, but she's very clearly several decades older.
At first I was somewhat hesitant of the idea, until I realized that my character is a half-elf and thus ages very differently from a normal human. So him actually having a visually much older wife wouldn't actually be all that weird.
They started dating in their 20s, but now that they are somewhere around their late 50s to early 60s, his wife starting graying, but he still looks the same as he did when they first met.

Now, this isn't really meant as me asking for a critique for or feedback on my character idea -I just wanted to explain how I got to this point-, but it did got me thinking about how these things would work and be seen in a world like Faerûn. How would people react to couples that are visually much older or younger than their partner, due to the different lifespans of different races? Would they have an issue with it, or would it just be an commonly accept fact of life?

(And yes, I am somewhat aware of the ... questionable implications of such a topic from a real world perspective. But I figured it's an important enough question from a world-building point of view, that we can put aside the irl politics for some time. )

In a fantasy game where so many species exist and bond togheter, what IRL may be considered uncommon can be more common. 

As DM i wouldn't make it a big deal out of it and treat it much differently than anythign else, unless it'd be among the player's wish.

Half elves don't actually have that much longer life spans than normal humans. They live to around 120, so at half elf in his 60's would probably still look to be in his mid to late 40's.

Quote from CharlesThePlant >>

Half elves don't actually have that much longer life spans than normal humans. They live to around 120, so at half elf in his 60's would probably still look to be in his mid to late 40's.

 
180 actually, and that's on the lower end. As written in the PHB:

"Age. Half-elves mature at the same rate humans do and reach adulthood around the age of 20. They live much longer than humans, however, often exceeding 180 years."

So 60 would be a third of their max life-span, which would roughly equal 25-30 in human years.

I would agree with plaguescarred that it’s probably more common in D&D worlds, especially in an inter-species relationship. But I’d also imagine people might react similarly to how they do here. Assume the older one is rich and the younger is a gold-digger. Or it was some kind of arranged marriage where the younger one was married off against their will for some kind of consideration, financial, political, etc. (I’m not saying those are always true. I’m saying that’s what people often think.)

Quote from Paefny >>

Quote from CharlesThePlant >>

Half elves don't actually have that much longer life spans than normal humans. They live to around 120, so at half elf in his 60's would probably still look to be in his mid to late 40's.

 
180 actually, and that's on the lower end. As written in the PHB:

"Age. Half-elves mature at the same rate humans do and reach adulthood around the age of 20. They live much longer than humans, however, often exceeding 180 years."

So 60 would be a third of their max life-span, which would roughly equal 25-30 in human years.

 Ah, good catch! 

 A lot would depend on the area they live in. Areas with several long lived species as well as humans will tend to see more of it. Areas with a dominant single species probably won’t.

I think you may be overthinking it. Unless they are making out on the street corner, people would probably assume a couple with a big age difference would be parent/child if openly affectionate or just friends if not.

But assuming it was apparent for some reason, I think it would depend on the cultural makeup of your world and where you are in that world. In a small village of mostly one race, they would likely think it "unnatural." In a big cosmopolitan city full of different races, I doubt anyone would give it a second thought.

Quote from Paefny >>

So, for my latest game, I've been thinking about playing a character who used to be a tattoo artist. I tried to find a picture for his wife, and I found one that I really like, but she's very clearly several decades older.
At first I was somewhat hesitant of the idea, until I realized that my character is a half-elf and thus ages very differently from a normal human. So him actually having a visually much older wife wouldn't actually be all that weird.
They started dating in their 20s, but now that they are somewhere around their late 50s to early 60s, his wife starting graying, but he still looks the same as he did when they first met.

Now, this isn't really meant as me asking for a critique for or feedback on my character idea -I just wanted to explain how I got to this point-, but it did got me thinking about how these things would work and be seen in a world like Faerûn. How would people react to couples that are visually much older or younger than their partner, due to the different lifespans of different races? Would they have an issue with it, or would it just be an commonly accept fact of life?

(And yes, I am somewhat aware of the ... questionable implications of such a topic from a real world perspective. But I figured it's an important enough question from a world-building point of view, that we can put aside the irl politics for some time. )

 
umm if both the (i assume human) wife and (half-elf) husband started dating in their 20's and are now both 50-60yrs old
makes me wonder:

• if half-elf people age at the same rate as humans atleast until maturity and then their aging slows down after that (to preserve the youthful look)
• if half-elf people age slowly throughout their lives (potentially making a 20yr half-elf look very childlike and a 20s looking elf being somewhat older then their appearance) 

depending on which way you lean could have affects on your world-building 

EDIT: also due to the half-elf still looking the same as he did when they first met, makes me curious if something else may be at play and if the half-elf has something else affecting their appearance/aging to such a degree  

As was already stated, half-elves reach physical maturity at the same rate as humans, then have their aging slow considerably.

Maybe the wife was an elf but she was killed by gnolls during a raid and then she was reincarnated into a human. 

In previous editions casting a wish spell stole the spellcaster years of life.

Maybe the husband is a cleric and the deity rewarded him with rejuvenection, but the wife chose to get old and die to go with her family in the celestial plane instead the divorce. 

The human mothers of half-elves and other species live more because during pregancy they adquire cells from their babys. This happens in the real life as micro-quimerism. 

Quote from 6thLyranGuard >>

As was already stated, half-elves reach physical maturity at the same rate as humans, then have their aging slow considerably.

That may be true however my mind seems to wonder if that's the case due to the following:

• Some half-elves live among humans, set apart by their emotional and physical differences, watching friends and loved ones age while time barely touches them. Others live with the elves, growing restless as they reach adulthood in the timeless elven realms, while their peers continue to live as children. 
• Half-elven coloration and features lie somewhere between their human and elf parents.
• Half-elf: Age. Half-elves mature at the same rate humans do and reach adulthood around the age of 20. They live much longer than humans, however, often exceeding 180 years.
• Elf: Age. Although elves reach physical maturity at about the same age as humans, the elven understanding of adulthood goes beyond physical growth to encompass worldly experience. An elf typically claims adulthood and an adult name around the age of 100 and can live to be 750 years old.
• Human: Age. Humans reach adulthood in their late teens and live less than a century.

Which leads to a potential that even though the half-elf is/has matured, it may not look physically mature in the same way as a human would - this is mainly due to the different phrasing between elves and half-elves and the "peers continue to live as children" comment

have always been unsure if that's a mentality, behavioural, cultural or an appearance comparison.. which could influence world-building (also curious how long each of them would be considered in their prime for but that's probably starting to drift of topic)

I'm pretty sure that it doesn't matter at all. D&D is an RPG. If the two PCs involved are having a good time, and aren't pushing the boundaries of decency for the game they are in, go for it.

In my opinion, those familiar with elven aging would likely see it as a natural, even poetic phenomenon - some finding it tragic, others beautiful. However, I don't think you need to worry about it.