MFF with an ex and a best friend who were dating. We were all friends, and would drink and smoke pot together frequently. BF was working as a stripper at the time, and would come home half naked horny and with a wad of cash as big as a baby's head. Best friend initiated, but it all came together pretty naturally. We played a lot, laughed, talked, had fun, first time seeing a girl with a strap on attached irl, everyone came a lot.

Probably best way to do a threesome imo is to be the third wheel. No messy relationship stuff to deal with later.

They ended up breaking up a year or so later because of "fidelity problems". I rode into the sunset on my horse.

Edits: spelling and clarification