So we both like each other and all and I do know that for a fact because he has told me multiple times. One problem was just in the way, I am 15 while he's turning 18 at the endish of July. I told him we are not having sex only for that reason and he respected that and was okay with it. Please have an open mind about this because I am mature for my age.
You can date him, but before having sex make sure you know the law where you live. An older teen can get in serious trouble having sex with someone much younger, even if it is completely consensual. At 15 you may not be able to consent to sex where you live. It differs country by country, and in the US and Canada it differs province by province.
You sound like you're mature enough and weighted the situation (at least this is how I see it in this post), so I don't see why would be a concerc to date if you two have feelings for each other and are on the same page.