Couchsurfing with gf and have no idea what to do

My gf and I are currently Couchsurfing through Central Europe. Right now, we're in Berlin staying with a nice (I thought) Turkish guy. Great flat, good vibes, went out last night to a Grillhaus and drank a ton of Raki. I can't really handle my alcohol, and I drank way too much and passed out when we got home. Woke up in the middle of the night to our host fucking my gf in his bed (I was on the couch). I legit froze and just pretended to be asleep. I haven't said anything bc I don't even know what or how to say something at this point. We're in this guy's house until Tuesday, and I'm on this trip with her though second week of April. My stomach is in knots and I have no one to talk to about it (and I don't even want to tell anyone bc it's embarrassing and makes me feel like a bitch). Thanks for letting me vent, I guess.