I like him but I don’t know if it would be wrong

I have a little crush on this guy and I’m pretty sure he feels the same way. I don’t know if it would be considered inappropriate if we were to date. This is where it gets confusing - my dads girlfriend has a best friend and they’ve known each other there whole lives well her son is this guy. My dad and his girlfriend aren’t breaking up anytime soon and they’ve even talked about marriage. The guy I like calls my dads girlfriend zia (which is Italian for aunt) which kinda seems weird to me (if we were ever to date). Let me know if u think this is too weird for anything to ever happen between us. Thank you