Am I wrong for thinking this is wrong?

Mimi

My ex boyfriend & I broke up a few months ago & he immediately started dating a young woman aged 23. He is 36 & I am his age. He took my daughter as a daughter. She was 12 when we got together & now she's 20. They still have contact w each other & he still helps her when needed. The part that bothers me is that his new girlfriend is only a few years older than my daughter & they have some of the same friends. It almost makes me feel like he's a pervert but she's of legal age. How would you feel in my shoes?