Just chiming in to reinforce what others have already said.
As you point out, there's a much larger difference between, say, 16 and 18 than between 26 and 28. You are both going through a very formative time, but you're about to embark on a qualitatively different experience that will mature you (hopefully
) in different ways.
And don't forget what Dale Kemp says - statutory rape laws apply in most states, at least for now. Exact ages vary, but, well, cover your ass and wait.