What is this, Sweet Valley High? Call me when you are pregnant and he leaves you for his own sister.
Here's my advice: Learn from this experience. The next time...play SCRABBLE instead of Monopoly. Scrabble is so calm and slow; it will never get you horny even when you're drunk.
I'm not seeing the problem here.
Except the alcoholism.
Lol ... hey, I felt weird when I awoke to spooning my younger sister after our Christmas party! She didn't know until I told her! Ha ha, I was weirded out!
So long as he's an adult and you're an adult I don't see the problem.