What's your question?
My friend used to date this guy in our friend group but broke up with him a couple of months ago, and I suspected he liked me while they were dating, and he started flirting with me again. But when my friend realized he was flirting with me, she seemed kinda upset but acted like she was fine. But the thing is I think I like him too and idk what to do.
Let's start with the obvious question: How does your friend feel about this? Is she okay with you dating this guy? I would talk to her first, find out if she’s cool with it. Ask her if she's okay with you dating him, and if she says “no”, then are you willing to ruin a friendship over a boy?
Second thing to look at is: Why was this guy flirting with you while he was in a relationship? That doesn’t seem very loyal. If you're looking for a guy, find someone you can trust and you know has a good track record with relationships. Also, you probably will want to know if he likes you back; there’s nothing more embarrassing than telling a guy you’ve got feelings for him and finding out he doesn’t feel the same way. Ask him how he feels about you or ask a friend to find out.
The third item to look at is that your friend doesn’t think you should go out with this boy. She probably knows more about him and his dating styles. She may be worried that he’ll hurt you.
The last thing to look at is if you really have feelings for this person. Some people think they like someone but really just like the idea of someone liking them. Find out if you really do want to date this person. And remember that the most important thing is if you're okay with this relationship; you're not just dating him because you feel obligated to by peer pressure or pity for this boy.
Remember you are in junior high, and this relationship probably won't last forever. It's good to look around and find what you like, but if you don’t think it’s a good idea to date this person then don’t; you do you! Be safe and have fun!