See.. I'm very different with most of you all on this matter.
I think age matters, but only until you're out of high school.
I mean, there's nothing socially wrong with it at all. If two people who are years apart in age are in love with each other, then, by all means, go for it. The thing is, a friend of mine put something very VERY clearly to me. High school is the time of self-discovery. It's a time to learn about yourself.
Even when high school is done, most people still are confused about who they are as a person. A Freshman is not gonna have the same life experiences and maturity level as a Senior in high school. I mean, yes, the Freshman can be very mature for his age, but there are just those walls that are just very difficult to climb at such a young age. Me and my boyfriend are two years apart in age (me being the younger) and there are already those huge maturity boundaries. I mean, yes, I am rather mature for my age as he says, however, there are just some things that I'm gonna have to learn in time and I thank God for giving him the patience to deal with me

.
Once you're out of high school, however, I think most people have discovered a good portion of who they are as a person, therefor, age gaps can be a little more leniant.
When it comes to young sexual encounters, I really don't think it's right until you're age 17 or even 16. The thing is, high school shouldn't be about pressuring yourself to have sex or have a boyfriend/girlfriend. It should be a time to be with your friends, shape your circle of close friends, and squeeze in relationships here and there to learn what you like and don't like in a partner, so that that way by the time you reach college, you know what you want in a life partner.
Sorry for ranting, but that's my view.