What should I do

I've been in a relationship with my boyfriend for over 6 months now and I really do trust him but some things just give me anxiety. I just want someone's opionion if it's just me being me or it's something that needs to be addressed. My boyfriend is popular he loves partying and going out with friends. About 2 months ago he had a drunk night where he went out with his friends he doesn't remeber most of it but he grabbed this girls ass and talked about cheating as well as going to a strip club but he told me the next day and he was so upset and so heartbroken that he could ever do that and I knew that he loved me and that sometimes when he gets drunk he gets messy. About a month ago, he's out at a party in not in the country but he says that he met this chill girl at a party and she walked him home and apparently they live close to each other. I was a bit anxious but said nothing of it and I heard nothing about her up until recently. Where he says I'm meeting a friend for drinks, and then doesn't reply for 3 hours. Usually when he goes out he tells me who he is with and where he goes and keeps in contact with me but he kept this a secret, I told him that I'm uncomfortable with it and I thought that he took that into account but now he's tagging her in things on Facebook and her told me yesterday they're meeting up again alone for drinks. Am I over reacting or should I question this?