Okay so my boyfriends friend (let’s call him Collin), has been in a relationship with this girl (let’s call her Daisy) for over a year. My boyfriend and him have been best friends for many years, about 4-5, and they’ve been through a lot together. Last night we went to the bar and I was 100% sober the entire night, My boyfriend and his friends were drinking. Collin is talking to our other mutual friend (Jake) and we (me and jake) see a notification from Tinder on COLLINS PHONE. He says some shady shit like “Oh idk why I have a notification from tinder wtf” and then walked away (and kept walking away the entire night). I told my bf ofc cuz why wouldn’t I, and then my drunk bf takes his phone and goes through it and sees tinder in his phone search history. Collin says “me and Daisy went through it together a month ago to delete our accounts” but then 20 min later he said “we went through it laughing at people’s accounts” like WHO DOES THAT. so we started arguing about how he’s lying (because i know damn well he is) and he gets up and raises his voice at ME like I did something??? He started getting super defensive when we told him we were gonna tell her but then was getting all sad and crying saying “bro i’m so disappointed you think that low of me”. super manipulative and gaslighting. So now it’s the next day and idk whether I should tell daisy or if I should just let it pan out. I don’t want to ruin my bfs friendship with him but Collin is a HUGE liar and lies all the time, can’t keep a job for more than 2-4 weeks, makes Daisy pay for everything. I feel horrible for her but my bf is really close to him. please help w advice