So for a while my gf and I have been talking about having a threesome with another girl.

So far the progress we have made is kissing a girl together on a night out. (Turns out she had a bf so we left it at that)

Recently though, one of her friends (lets call her Kacey) came down (she lives pretty far away). Kacey is a hot 5ft5 redhead. We’ve always been a bit flirty but it’s always been harmless. Well at one point my gf had gone to have a shower while we were watching TV - after 2 minutes her friend comes out with “So a threesome?” We both burst out laughing. Kacey started asking me questions about it, one of them being “what kind of girl are you looking for..” she then looked at me with pure lust. I knew she wanted it - and since that moment all I’ve wanted is to fuck her silly little brains out. We kept chatting about it as she cuddled into me, her head on my chest looking up. My hand was tracing down her back until it fell lightly onto her arse. She started put her hand on my thigh and slowly moved it up as we talked about all the different positions I want to try until her hand was on my shaft (over my shorts). My dick was ridiculously hard at this point and so so gently she stroked my shaft over my shorts. We heard my gf coming and although we stayed cuddling (normal for us) we had moved our hands back to a normal position. Nothing happened after that - the friend left that night. We havent spoken since. I haven’t told my gf. Its a tough one to navigate, although we want a threesome I’m not sure my gf will like the idea of it being her best friend.

Also yes I’m probably a dick for this.