Is it normal that i have thoughts of my ex having sex with another man

Let me explain my situation first. I am a 27 years old male, I’ve only dated one girl in the past and I was 22. At first, our relationship was great. Our sexual relationship was great! On some occasion while having sex, we imagined as if she was doing it with some of the people we knew, I was fine with all that as long it was fantasy.

Later we started to dispute quite frequently. This often happened because she was flirting (I believe) with other guys and I end up being jealous. Sometimes after our dispute, she would flirt even more. If I could describe her personality in some few words, she was manipulative, self-centred and baby like attitude. As our relationship was not working, I later put end to it.

Like a year after our breakup, I started to get aroused about her sleeping with some of her guy friends. I also had thoughts of her having sex in a missionary position with a black guy who would then ejaculated inside her.

I consider myself sexually curious, and before I knew her I was already interested in various sorts of porn like shemale, BBW and gay. However, since then I started to be interested in cuckold, hotwife and interracial sex, I even fantasized sucking a black guy’s penis. I know that I am not gay as I like women and I am even trying to date one now. I would like to note that I despised sexual affairs, I wouldn't want that to happen to me, but at the same time, the idea of a sexually open or promiscuous woman turns me on.