your crewmate is messed. i would never ever allow a MMF threesome if i were the one with the girlfriend. also, MMF's are not my thing, but congrats on giving that girl probably the insanely pleasurable experience of being sexually satisfied everywhere by two guys and fulfilling her semi-gangbang fantasy. and as long as you're secure about your sexuality, ORJ_Jos is right, MMF's are not "gay" at all as long as there's no awkward dick-touching (like one in the ass, one in the pussy). i have a question though: where did you "finish"? did you use a condom?
my girlfriend expressed interest in doing an MFF later down the road... my second threesome is about to come true~ ^^
Edit: oh, and don't call them lol. you'd just look like a desperate horn-toad and might just annoy your crewmate a little bit. if you showed her a good time, she'll be trusting you, and when she'll want to do it again, you'd probably be the first to be contacted (unless she actually gets more turned on by random strangers). i foresee more threesomes in your future.