Age difference.

So there's this guy that I met at work and he's so amazing and he's such a gentleman. We've been talking for a while now and it's getting kind of serious. I'm 19 and I really don't mind the age difference, he's 30. My problem is that I don't know how to tell my mother that im seeing and especially his age. I've talked to my cousin that's 24 and he says that it really shouldn't matter, that im an adult now and make my own decisions. But I just wanted advice on how to tell or at least help my mom understand the situation. The guy is very supportive about it, he's willing to meet my parents and tell them anything.