<human>: My boyfriend has always had a problem with flirting with other girls and talking to them inappropriately. He has never actually cheated on me, and I doubt he would. We have been together for almost two years, and he really does love me. He isn't a bad guy. 

On the 4th of July we went to a party together. We both got pretty drunk, but not exactly wasted. Once we were home a friend messaged me saying "Hey. Just wanted to let you know your boyfriend sent this message to another girl." 

The message said "Hey. You're so hot and beautiful. I couldn't keep my eyes off you at the party. I have wanted you since I have known you. If you ever want secret sex, let me know." 

He sent this message after we were home. He deleted the message originally trying to hide it from me. 

He says he was drunk, and he didn't think about the consequences. He didn't think about it hurting me. He really does feel remorse, but I can't trust him again. I don't know how to deal with this. He makes me angry anytime I look at him. I feel so disgusted and let down by him. He is supposed to be my best friend. Does being drunk really give him an excuse to act that way? Especially when I've dealt with similar issues like this in the past with him? 

I really don't want to leave him. We do make each other happy besides things like this. It just feels so unhealthy, and I'm hurting. Even if I did want to leave him, I have nowhere else to go.

What should I do in this type of situation?

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: Boyfriend got drunk, asked girl to have secret sex with him, got caught, and now I don't know how to deal with him. (trying not leave him)