I was a lifeguard at 15, and at one time I had a semi-secret affair with a 19 yo woman, for the summer.
At 17, I had a gf who was 15, and for a time I was 18 when she was 15.
I have absolutely nothing but fond memories of those years. And the old gf remembers it very fondly, too. No harm, no foul. And certainly no regrets.
:)