Am I a terrible person?

I have been with my current boyfriend for 5 years now and I truly do care about him. But the problem is his best friend is my ex boyfriend, the first person I've ever truly loved. My boyfriend and I have a great life together and a good relationship but every time my ex comes around (which is almost everyday) all those feelings come rushing back and I second guess the relationship I'm in. The only reason we broke up was because we were in high school when we dated and my dad made me stop seeing him because he found out we were having sex. I guess I'm just wondering if the feelings will ever go away or if I'm making a mistake not trying things out with him again? And am I a bad person for thinking about my ex when I have a man who's in love with me?