drunk 3some

I had a drunk threesome with my girlfriend and my best friend (also a guy). His penis turned out to be huge. My girlfriend was a virgin when we met so all she knew was my dick. She blew me while he fucked her hard from behind. I couldn't help orgasming quickly, and so I sort of slumped down afterwards and held her while he she was pounded for what seemed a long, long time. She kept telling me the whole time how good it felt. I was happy she had finally got to feel another dick.
The next day she was sorry and crying and said she felt guilty, even though I was cool with it. And my friend has never mentioned it to me since, like it never happened.
I wish they would just see it for what it was. The two people I care about most making each other feel good. I don't really understand why it had to become so fucking awkward.