[MFM] What started as a joke ended up in a threesome

About 10 years ago (both 20 years old) me and my (ex)gf ended up in an unexpected threesome with a friend of ours.

It was a usual Saturday when my girlfriend and in went to town to have drinks with some friends. We started at a cafe and after a few drinks we felt that the mood was good and wanted to go to a party.
We ended up in a alternative club in town and everybody was enjoying theirselves and had more drinks to the point that we didn’t care anymore.

My (ex)gf is about 5’6, has brown hair, a cute B cup, and was a little bit curvy but had a really nice and firm ass.

I am 6’3, a normal shaped body, not very athletic nor chubby

She was always very open minded about sex and could easily talk along with ‘the guys’.

In the club we started chatting with a good friend of me and somehow the subject changed to threesomes. More specifically the ‘tower bridge’ (girl on her hands and knees while being fucked from behind and sucking another guy). She really liked to tease so she said it sounded pretty good to have two guys pleasing her. It was obviously a joke but we all played along pretty well. We also agreed on giving each other a high five when in the tower bridge position.