Further to Daedric9's answer, there's usually a 'whorehouse' nearby when you pickup the hookers, it has a sign outside it. Run upstairs and hit the "A" button near the bed.

You only need one but it helps when the tavern is full of people watching you do the dirty deed.

Get two people (they don't have to be whores) to have sex with you at the same time. As a very good female hero with high attractiveness, I was able to get four or five at a time. Bowerstone Market was just full of randy buggers!

The Best thing to do is to get a Your wife Do the Come, Hither Dear Emote on her, then go to a person That loves your Character, and Try come, hither dear Emote on them, if this does not work, Just go to Bloodstone get a Whore, Get her(Him) To follow you and then go to a bed and pay her and then..... Blee Bloop Swinger acheviment acheived!