My friend slept with my crush, now what do I do?

This is a tad lengthy so please hear me out. I started uni this year just after breaking up with my boyfriend (we went out for a year and things were all good and pretty serious. We broke up cause of distance). After coming to uni, I went through a bit of a slutty stage for the first couple weeks. Near the end of the first term I had sex with this one guy who was the first person I had sex with (since my ex) that I genuinely wanted to have sex with him as a person (it happened twice). Since then, pretty much every night out I see this guy and get with him. He's in a flat with one of my friends, so we see each other in passing quite a lot as well. We never chatted a great deal and nothing really ever fully happened. He's really super shy and went to an all boy's school so it was always quite hard to get him talking and not just going bright red when he's sober. I started to develop quite a crush on him and two of my friends kept on trying to convince me to text him.

However, plot twist, one of those two friends got black out drunk one night and was apparently hitting on him a ton. He apparently kept on pushing her away, but after a few hours they went home together and ended up having sex. My friend feels really bad but I've kind of lost trust for her. We had been friends since school and she had known how I felt and had seen me in my last relationship. I laughed it off to her because she was really embarrassed about other stuff that happened that night and had other stuff going on. I haven't talked to the guy since yet but don't really know if I should / what to say. I know I'm probably over reacting but I just don't really know what to do. Please help!!