Confused Asf!!! Someone help!!

(Im not saying the one person's real name)

So this guy "Alex" who I have known since I was 12, me and him started talking again and found out we liked each other so the one day we went somewhere and had sex then a week or two later we had sex again. Then me and my ex Triston got back together because he wanted me to give him a second chance so I did. I was still talking to "Alex" and yesterday "Alex" picked me up and we went and had sex again! And we like each other but I have a boyfriend Triston. But....he is texting/flirting with his ex gf "Alice" and she has had sex so many times and gave so many bjs she is a whore. And Triston is getting mad because I don't wanna have sex with him, well he is small and sucks at sex I don't know how that's possible!!!!! And he is probably cheating on me.

"Alex" is a great guy, I have known him since I was 12, we like each other, we have had sex, and we have some things in common.

I don't know what to do. Someone help me, message me or comment please.