My first threesome [FFM] (it’s my first time posting, hope you like it)

It’s gonna be little bit long, so sorry in advance.?

Some backstory:
My gf and I met each other at the dormitory where we lived the past year. When we met she was with a girl she befriended and we all got to know each other together as a group (BTW I was with my friend but he has a gf so I’ll leave him out of the story). So as time went we all became a small group of friends and every weekend we would go drink or do something together. My gf and Jane we’re roommates.

As time goes on we all get pretty close to each other. After about two months my gf and I started to joke around with our girl friend (I’ll call her Jane so it’ll be easier), so we start making sexual jokes and joking that she’ll eventually will have a threesome with us. So it went on for a while and she was being kinda shy and saying no, it all was more in a comical sense.