Maybe 2 weeks ago (could be 3 I'm not sure), my friends went out drinking. We planned to stay in my friends house after because her parents were away. That's all okay. I don't drink and neither does my other friend, so we went to be the babysitters. Two of my other friends also didnt drink, but couldnt stay over. The night goes on, we go back to my friends house. She decides to invite two of our good guy friends to stay over, which is okay. However, my boyfriend, who couldn't be there, wasn't happy. He tried to get me to leave, which I wouldn't do because I was the one of the two only sober people able to stay over to look after people. And besides, I wasnt gonna give him that power over me. Keep in mind there's about 9 people here, 4 sober but only 2 could stay, me being one of them. I wasn't just gonna go and leave my vulnerable friends because my boyfriend wasn't happy because he wasn't able to stay over. That's all good and well, he's in a bad mood etc, he gets over it, night goes on etc etc.

Then, a few days later, I find out that he went bitching to his ex girlfriend. Off her boyfriend, who happens to be my cousin. I was fuming. He's been texting his ex for a good few months, they're super close. But I asked him to never talk about me or our relationship with her. And he went and did it. I'm still super hurt but he isn't sorry for doing it. He thinks he didn't do anything wrong. When I asked him about it, he said “shes the person who knows me second best in the world." They've been together 3 times.

Am I in the wrong for looking after my friends?