>>33403199 (OP)I started dating an 18yo when I was 27 and we've been together for 4 years now.
From my experience, half the women you know that are about your age are going to irrationally hate your guts and go out of their way to make sure you're socially ostracised. If your mates are their boyfriends, then you're about to learn how absolutely whipped they all are. Her friends are going to split down the middle, some will find it exciting/interesting (as long as you're cool) and others will be so freaked out they wont talk to her anymore.
Basically, you're going to find out who your real friends are real quick if you date this girl.
Your social circles might be a lot more loose with dating so it might not be as big of an issue, however I'd expect to catch a lot of flack and to be under the microscope. If things go south, you're automatically going to be the bad guy. You really need to behave yourself, striking a good balance between being a cool older guy while not fucking her up.