Cheating Bf? Adviceee

Hey I really need advice! I have no idea what to do or to even think. Backstory: My boyfriend and I have been together 9 months and we’ve known eachother 2 years going on 3. We dated in 2019 for 5months but broke it off, then a year later we reconnected and have been strong ever since. We literally vibe and are the same. Ik a real relationship when I get it because we got each others back, I’ve met the family, we take vacations his friends and everyone knows about me, he even posts me no hesitation confessing his love for me. We talk about real life serious topics and plan to make them happen.(such as having a kid and getting married) he’s even asked me to move in with him.

Fast forward long story short lately he’s been acting weird, I went through his phone a couple of times and have noticed new numbers not saved. 2 of them have been females that he’s been texting flirtatiously, but the thing is I let it slide because 1 female was from out of the state and the other denied him bc she had a bf and he offers to be the side dude. I let him slide because he’s been working doubles for the the last two months working long hours and when he’s not at work he’s with me. So when does he have time to cheat? Lastly I’ve been noticing this one girl number in particular that he facetimes and text constantly but always deletes later.

Right now I went through his phone because again like I said things have been weird and I went through his messages and found nothing because in the past we’ve had a incident and he’s knows I’m crazy, he started getting smarter so I don’t find anything anymore but I see messages between him and his best friend!! Talking about this girl that’s supposedly his new gf and the best friend asking what happened to me. They exchanged the mystery girls info and pics but I didn’t see any of that because they send snaps to eachother that disappear and they ft eachother to finish talking. Should I leave him or confront him?? Or play my role? I want to build my facts up and entertain other ppl so I don’t look dumb and he’s the one that’s dumb. He can be a narcissist at times and think I’m not capable of hurting him, he thinks whatever female he has will always come back...

I think this all is a matter of talking and entertaining females and not actually doing anything but idk what to do. I’m tryna remain calm because if I leave I’m not leaving quietly it’ll be a mess. I want to call the number he’s been on ft with, find girly social media and some other things. Help!

Extra things about weird stuff he’s done:

me and his best friend have the same bday and one time we were otp talking to eachother and he starts talking to his friend about zodiac signs and he specifically mentioned that he had a best friend who was a Aries and how her bday was ... but didn’t mention mines being the same day. Why’d he mention her but not me unless he didn’t want them to know about me?

I’ve seen him swipe up on a girl saying he’s single, let another girl call him Papi, and him tell another girl that they compatible(but that’s been addressed and I moved past it and my trust has been messed up since)

He works with this girl who he said they have a great vibe and should “talk more”