i got the tea app and figured out my situationship was talking to his ex the whole time (F 19)(M 20)

THIS IS A LOT IM SORRY PLEASE HELP ME At the very beginning of June I was at work when a guy came in and started up a conversation with me while i was checking him out. He liked my tattoo nd started small talk abt how he had moved to the area for college a couple months ago. The conversation was flowing good, so when he had asked for my number i gave it bc everything seemed very natural. It took me 2 days to reach out but after that we started texting+snapping and planned to hang. We hung out after about a week talking and the FIRST hang out maybe should’ve been a red flag?
I asked him if he’d wanna go birthday gift shopping w me for someone but it just seemed liked he was in a rush and almost uninterested? but at the same time he was still chill. We got back to his apt not long after being out and long story short he made a move but i was on my period so we just stuck to oral stuff.
Our second time hanging out we had gotten boba and went back to his place again where we only made out and played w eachother( if yk what i mean).We ended up going all the way after the 3rd hang out and from that point on our hangouts consisted of smoking, and fucking.
It was july 4th and i was at an air bnb where i invited him to come over later at night which he did. We had gone a couple rounds and me being a little tipsy i wanted to establish some boundaries since we were SLEEPING TOGETHER. I kept it simple and short about how I didn’t care if he was kinda talking to other ppl bc we’d only known each other a month so far and he didn’t owe me anything, but if we were going to keep what we had going on i didn’t want him to be going around fucking other girls especially without me knowing (simple request right?).He had said that he definitely wasn’t fucking other girls, but that he was “kinda talking” to someone, but to me he seemed liked a genuine guy and from what i knew abt his work and social life i thought he was being straight forward.
As time went on i could feel he wasn’t putting in as much effort but i figured it was bc we both were busy but also getting more comfortable with eachother. He had also yet to ask for my instagram which isnt a big deal ik but still he used his and knew i had one so i was just confused as to why he never ask abt it? but ig i didn’t either so
Fast forward to Wednesday (yesterday) when i asked my friend to put him on the new tea app js for fun, bc i rly wasn’t expecting any responses. But after an hour one comment had said he def gets around and to wrap it up, and another had said she was planning to hang with him for the first time and go to his new dorm this wknd. Mind you he js moved into it last friday which was the last time i saw him bc i came over at night once he finished unpacking. That hangout had felt different to me bc we fucked on my period which wasnt the first, i had js gotten sm blood on him AND his blanket(kms) so it kinda felt like a bonding experience and we both laughed💀
Anyway SOMEHOW his ex of like 5 months friend saw the post and sent her everything which i’m assuming she then sent to him to confront him because he ended up texting me that night saying “assuming u saw the tea app yea” because i was being v distant that day. I told him i did and that i js felt weird bc the comment said they were supposed to fuck the wknd and that was like my one boundary, which he then said was crazy bc he rly didn’t have any plans (dk if he’s lying or not but that girl is irrelevant)
He proceeded to tell me it’s best if we cut ties because he had been “leading me on nd talking to someone else”, also that the “tea app but him on blast and made him realize small things like this” but also still tried to hide the fact it was his his ex who he was talking to again and literally that night had given her my snap but just ignored it and didn’t even bring it up. I just don’t understand men bc i gave him chances to pull away and distance himself but he was the one who would initiate our hangouts and but put more energy when I WAS pulling away.
Not long after i texted him back his ex added me, which she then proceeded to ask if i knew him and told me she was his gf of like 2 years and was starting to talk to him again since 2 MONTHS AGO which was a little after he asked for my number at work. We had a really long conversation abt him and what he has been lying to us abt and hiding. I’m just so confused as to why he would even entertain me when he was wanting his ex back.
Basically today i had gone by his place to get my bra i left and we had a little small talk before i asked if he had fucked her while we were talking which he proceeded to tell me he did and followed up with “ik it’s fucked” which is what he kept saying the night before abt the situation, like you did it? u had full control on what u could do? He just unadded me on snap too and when i asked why he said bc we “ couldn’t fw each other anymore” and that it was “for the best” and i’m assuming now that his ex knows she told him he couldn’t fw me and is keeping an eye out bc from our conversation i rly don’t think she’s gonna let him go.
Idk it’s just so weird to me bc she said he was saying he missed her and that they did hang out some over the 2 months so if he was getting it from and and wanting to get back together why even mess with me? He had introduced me to some of his friends and would talk abt future plans so i just don’t understand what his intentions truly were with me especially since he dropped me now, like was it really all just lust? he would’ve kept it going if it wasn’t for the app so i’m just confused on if he actually liked me and if he did why would he give up so easily for his ex who he’s already been in a relationship with that didn’t work out