Is age more than just a number?

Ever since I was in middle school, I always like older guys. For example, my first boyfriend was 16 and I was 13( we were in the same grade though). My mom liked him alot. After him, I got a boyfriend who was a 17 year old senior. I was 14 and a freshman. Our birthdays past together and when we broke up I was 15, he was 18. Now I am 15 about to be 16 in June. I have a boyfriend and he is 18. My mom thought my last boyfriend just wanted me for sex because of his age. I haven’t introduced my mom to him yet but I am afraid she will react crazy. Am I wrong for liking older guys? What should I do?