I like the guy but he is a total prick what should i do?

I've been friends with a guy for ages and he has been flirting with me for nearly a year. He was with one of my friends for a few months they have been broken up for 3 months now. We had all gone to the ploughing match that was being held in our town. We were all sitting on a trailer i was sitting beside him and then he leans in on me and kisses me right in front of her. I went to school the next day and he went back to the ploughing. Yesterday another one of my friends told me he got arrested for holding a girls *** and she asked if it was me i said no cos it wasn't. At the ploughing he also told me he was liked me since the 1st day we were talking and was stupid for not doing anything. Last night he changed his status on facebook to in a relationship with this girl from cavan (a county up in the north of Ireland we live in Kildare near to Dublin)