17 year old dating a 21 year old?

I'm 17 and I'm dating a 21 year old.  We have only been going out for a couple weeks, not official or anything.  The age of consent where I live is 16.  I've dated guys my age and I don't really connect with them, I find a lot of them are just looking for sex, or they don't have a job, or they can't drive so I have to drive everywhere, or they are way too immature.  I really have a connection with this guy but, he is 21.  Age doesn't really matter for me and it doesn't matter to him either, I know he's been with a woman who is 40, and the youngest he's dated was 18.  I was telling my friend that I'm dating someone who's 21 and she thought it was weird, I just want to know other people's thoughts?  Just curious to see if anyone has been in a situation like this, if things keep going good like this, eventually I'm going to have to tell my mom, anyone have any advice for how to tell her?  She knows I go for older guys around 18 or 19 but, 21's new for me.  I just find it very attractive that he lives on his own in a nice house, has a nice car, pets, a good job and really has his life together.