Binding Oath

You seal an agreement between two or more willing creatures with an oath, using ritual blessings and toasts during which both oath and consequences are clearly set out. If any of the swearers break this solemn vow, they are struck by a curse. The caster may choose 3 effects from the bestow curse spell with unlimited duration, a fate affliction, or another penalty at the GM’s discretion.

A dispel magic cast using a 5th level spell slot or a wish spell also ends it.

At Higher Levels. When you cast this spell using a spell slot of 6th or higher the spell level required to break it increases to the spell slot used to cast the spell.