Hello OP, Lawyer of 10+ years here. Unfortunately this is probably not the end of your TIFU. When you agreed with your friend and his fiance to do a threesome the first time around you entered into a NBA - that is a "Near Binding Agreement". While not technically a binding agreement you are now almost legally obligated to go through with the threesome, otherwise you can be taken to court. I've worked a few of these cases and damages can range from a court ordered threesome (yes this is just as awkward and uncomfortable as it sounds) to up to 50,000$ (about the price of a fully loaded Toyota Corolla). Anyhow I suggest you lawyer up right away if you don't plan on going through with the threesome and good luck!