Am i over reacting or do i have a reason to be mad?

my x boyfriend has been trying to get back with me for the past few months but the more i give into it the less he seems to try. we had a conversation about trying to patch things up just last night and it was going good until we ended up getting into the dumbest argument and we hung up. i found out that an hour later he left to vegas with his slutty friends (i've seen them sleep with up to three different girls PER WEEK) to las vegas to attend the EDC thing. hes always arguing with me for partying in our town, even though he is there with his friends. should i be angry? or do i have no right? did i lead him to this?