Help with my chance of a lifetime.

[CheckCheckFold]

This is going to be kind of long to give you a good back story to help me out tonight.

Tonight we are throwing a party at our place for my gf's birthday. She's turning 23 (last quarter senior) and is living with me (I'm 26 grad student). We met each other at an e-party of close friends. This was two years ago. The e-party consisted of me, her, her sister, this guy lets call him M and his gf S, and another female friend of ours. Like all e-parties, it gotten pretty heavy including petting but all of us are new at this and it didn't go beyond that.

Fast forward to about a year ago, me and my gf are a serious couple and it was my birthday. M and S and me and my gf had some e and we had a little fun with each other but again it didn't go beyond me taking S's blouse off and fondling her boobs. My gf didn't get any of her clothes off. M [censored] up the situation by saying out loud "Hey CheckCheckFold, lets go down on these girls and then switch? Yeah?!" He was beyond tactless.

Btw, purely looks wise, M and S are about a point better looking than me and my gf. They pretty much always are the hottest couple at a party.

Sooo, fast forward to today, We are throwing a birthday for my gf and M and S are bringing over 7 pills of e(that's all our provider could give us) that I ask the guy to get for me which he was very glad to do. This all sounds great but there are complications that I really need help straighten out.

My gf and I think we are gonna need 2 pills each for it to be a good roll. That left 3 for M and S and my gf's close friend who is our other roommate, lets call her A. Now A is very very hot, and pretty slutty, but she is not attracted to me at all I don't think, and I think she's fake and annoying a lot of times, and we are roommates. She's in the picture because for some reason my gf promised her a pill a couple of days ago and she lives with us so there's no way of avoiding her.

Anyways, it's just seem like I could be getting too much of a good thing here and am confused out of my mind as to what to do. Or I'm scared that this situation could [censored] up my relationship with my gf and I'm uncertain how to deal with it the right way.

I'm a pretty clean stand up guy (the kind that parents adore) so this is a chance of a lifetime as I am certain that I will never have such opportunities again as this is my last year in school. But I really don't want to [censored] up my relationship with my gf in any way because I love her. We feel that we are pretty much gonna get married and such as we both have hung out with each other's parents and have talked of a serious future.

I'm bewildered as to what to do. OOT please give me some experienced advice on how to handle this too good to be true situation happening tonight!