Most Helpful Guy
Its borderline. Generally speaking 3 years different is max for minors - but it can vary from case to case. I think parents should be aware of it though, but be aware that it will be frowned upon. Also sexual stuff should still wait as 4 years in that age-range is quite a lot of a maturity gap (think of your maturity levels when you were 4 years yougner and you know what I mean).
That being said I find it ridiculous how people say he is an adult and you not. Why? Because the law. People should start using their own view. you don't just are a child when 17 years and 364 days old and then turn an adult one year later. Its a process of developing.
Also age-differences like this are more common than you think and CAN work out quite well when treated right. Obviously they can also backfire quite a bit.0