an I a horrible person

So I’m kinda been hanging out with my ex’s ex best friend let’s call him Jj . My ex cheated and left me when I was pregnant , and then got the other girl pregnant . And when I first found out he was cheating on me jj was there for me and actually stopped talking to my ex . My ex is there for our daughter when he wants to be, but Jj actually goes out of his way to see us . But there’s also another situation one of my best friends use to date him 2 years ago he try to get back with her a year ago and she has no feelings for him at all .

I’m developing feelings for him and I want to see him all the time and talk to him. I feel bad but I can’t stop my feelings I’m I bad for this ?