Would it be a bad idea for a character to date a Marid

I just thought looking at some old art of them being depicted as sexy blue girls that it would be fun to date one. Although their personalities sound complicated.

You can date anything if you put your mind to it (and they consent 😁)

This probably belongs in Lore & Story; the two immediate challenges that spring to mind for me are the no-doubt alien mindset of an elemental/genie, and the environmental considerations of their extremely aquatic environment.

(If all you want is "sexy blue girl" perhaps a Water Genasi would be closer to home?)

It is worth noting, if your character’s only motivation is “sexy blue girl based on their art,” that feels uncomfortably close to objectifying female characters for their looks.  Not saying that is something you are necessarily doing, but your thread’s focus on the physical as the basis for “fun”, with personality relegated to an incomplete secondary thought, does read a bit that way.

Just something to keep in mind if you do go this route.  Keeping the question of “is this objectifying?” in the back of your head, and using that as a lodestone guiding some of your actions, can help avoid crossing the line into creepy and making others at the table uncomfortable.