Do I leave him or should I stay?

I'm so in love with this man.. Never felt anything like I feel with him. And everything was perfect up until February. 2 years of a perfect relationship.. All of February I got messed around on, begging of February there this girl that I always felt something fishy about, an I always asked him who is she, have you talked to her, I always got a no babe. Just last week his bestfriend is dating her an they wanted to match (smoke all together) so I say why not an him and his girlfriend get in the back of the car.. The girl I hate but shouldn't have because she was nothing right? Well.. I don't care what anyone says there's this site that lets you see every text, deleted text.. An so on on your partners phone.. I told him about it he said your going to want to break up with me I said well then let's do it together I texted 2 men this hole relationship.. One was in the beginning an I told him about it.. And he texted one girl in the begging I saw on his phone to I thought we got that out of the way that was 2 years ago, the other man I texted is in the nba an I didn't even flirt with the man an he's a star! But I'm wrong because I talked to two people.. Anyway we did me an the two things he knew about was the only thing there.. Now let me remind you this just 2 weeks ago I found out he hung out with another girl an smoked with her he picked her up they smoked he dropped her off.. She said they had sex but she really says that about everyone an puts her self to be a hoe he said he'd take a lie detector test and pass and everything else all of her an his friends said they didn't.. So I really had trust he didn't that was in February when he did that. But the texts we did his phone another girl came up from the beginning of our relationship, so now he talked to two girls in the begging.. One just casual talk.. One really flirty. Then in February he talked to the girl I hated.. For like 3 days the one I let him pick up in his car so we could match, talking about I want to come Netflix an chill so we can watch scary movies and things like that they never hung out but I feel it's still as wrong. An last but not least one other girl he wrote while we were arguing saying she was cute an to him him up. It seems like a lot but 98% of the time things are great an ice never been so happy. He says we can get better no one had sex with anyone we were both wrong we both kinda cheated but we both need each other we shouldn't take the easy way out when we need eachother the most. An all that I know it can get better I know anything possible but should I give him the Bennifit of that? What would you do..