u/Harrycathy

Cuckold

Cuckolding involves a couple and a third person who has sex with one of the partners. While cuckolding can include people of any gender or sexual orientation, it typically involves a married couple and a man outside the marriage who has sex with the wife

Cuckqueen  –

is like cuckolding with the gender roles reversed. The man has sex with other women while the wife does not.

Hotwifing – 

when a husband encourages his wife to sleep with other people, usually men. It’s different because it lacks the humiliation aspect of cuckoldry.

Threesomes – involve a couple and someone else, who could be any gender. They are typically for everyone’s enjoyment, do not include humiliation, and may be a one-off

Swinging –

where couples swap partners with other couples, can include up to full penetration (hard swapping) or less than full penetration

Open relationship -

partners are allowed to search for and have sex outside their relationship.

Polyamory – 

a relationship structure where one or more members can be romantically or sexually involved with others. Humiliation doesn’t play a role, and some people may view it as an orientation