My friend who I'm close to is having a party this weekend. I really really want to go but my ex is going to be there. We broke up in September and I made a mistake by sleeping with him after the break up. Since me and him had sex he has not spoken to me, he has only messaged me at 2AM and treated me like a slut. I really want to go to the party but I know he will be there? Any advice? Help? If I see him with a girl I will end up spilling a drink over him.