I came inside my girlfriend (26F) in front of her best friend

I'm (28M) currently travelling with my girlfriend (Anna, 26F) and her best friend/housemate (Mary, 29F). My girlfriend has quite a slim and petite build, not well gifted in the bust area but a fantastic ass. Her best friend on the other hand, has a rack that's quite hard to ignore. She left her bra and panties in the bathroom the other night and I saw that she wears a 36DDD. Her ass on the other hand is quite average. But nonetheless, I have admired her cleavage a few times now. It's hard to keep your eyes off them when they're on display.

Yesterday we had a layover of more than a day and we got complimentary hotel stay with the airline. The room wasn't too bad - it was free so, couldn't complain. It had two single beds and a decent view.

After dinner, we came back to the room to shower and get ready for bed. We're close to the end of our trip so we're running out of clean clothes and Mary walks out of the bathroom in a very sheer tank top that is barely containing her braless tits. I'm mesmerised by the way they jiggled with each step she took. And to top it all off, she jumps into bed and I could have sworn I saw a nip slip. Honestly, a part of me wonders if she was trying to tease me. At this point, Anna and I had already showered and gotten into bed. And since it was just a single, we were spooning with her ass pushed quite tightly against my crotch. Some blood definitely rushed to my cock as I saw Mary's tits but I hoped Anna couldn't tell.

We're chatting in bed before going to sleep and I start to feel Anna's firm ass start grinding against my crotch. Under the covers, my hand was already fooling around with her nipples anyway, periodically making them and myself hard. It's quite hot where we are so we were all wearing just a shirt and underwear. I slowly slip my, now erect, cock out of my boxers and guide it between her legs, nesting not so gently against her warm pussy. As the grinding continues, she starts to get wetter and wetter until my entire cock is drenched in her juices and there's almost no friction as she fucks me with her thigh gap.

After a few minutes, I can't take it any longer and I suddenly pull her panties aside and slip my wet cock into her even wetter pussy and she gasps. Mary frowns and asks if Anna is alright. She passed it off as an almost sneeze and I continue sliding my cock in and out of her under the covers. All the while, Mary is now talking about her dirty laundry and how she's running out of clean panties to wear. Call me a pervert but Mary talking about her dirty panties and the thought of them brought me almost to the edge so I stopped a bit and then started again. Mary suddenly sits up, making her tits jiggle through that tank top that was barely containing them (still felt teasingly deliberate), "Oh I forgot to moisturise." she said. And she starts dotting cream around her face and that's when I lost it and gave one last deep thrust inside Anna and unleashed my load.

For extra context, we'd be travelling together for about a week now and sharing a hotel room the entire time meaning Anna and I were unable to have sex this entire time. So this was about a week's worth of cum just shooting out into her. I buried my face into the hair on the back of Anna's head as the orgasm was pretty intense and we just lay there for about half a minute as I pulsate inside Anna and the waves of pleasure come and go. Mary asks if I'm alright and I just let out a yawn and say I'm getting tired. After a few minutes Anna, rushes to the bathroom to clean up and then we went to sleep properly shortly after that.

This morning, she tells me that I shot so much cum into her that more started to leak out in the middle of the night after she thought she'd gotten rid of it all. She got turned on by that and so she used it as lube and fingered herself until she finally finished. Being a man that just finished, I was unfortunately passed out but I wish she'd woken me up for more fun.

I'm quite a lucky guy in that Anna is usually able to cum from penetrative sex alone but unfortunately she didn't cum with me this time. I promised I'd make it up to her soon. We're going on a two day hike now where the three of us are going to share a tent. The horny part of me is still thinking that Mary was teasing me on purpose and I'm fantasising about a threesome in the tent but let's see how it goes. I'll post an update if anything happens. Wish me luck!