<human>: Could you distill the essence of the text into 1-3 sentences?

My SO is off to Mardi Gras with 3 of his guy friends. I've read and heard about Mardi Gras and all I can think about is the boob flashing, promiscuous women and hardcore drinking/partying side of it. I should also add that we have had some trust issues in the past. I caught him continuing to see a girl who he'd previously had a one night stand with, 4 months into our relationship. He tried to hide this information from me (ie. told me he was at the gym when he was really at her place). He swears he told her about me when we started dating, that he never cheated or touched her since, and that he stayed in contact with her only because he wanted to remain friends and because of her depression. It was so long ago, we've talked about it over and over, but trust has never been the same since. Reddit, should I be concerned? Is Mardi Gras really what I think it is?
<bot>: SO going to Mardi Gras, worried about the situation because of how I see Mardi Gras and because of our trust issues. Should I be concerned?