I did have one girlfriend with flaxen hair that went to her mid-back when I met her; by the time we called it off, it had gone to just above her rear end. I was very open with my fetish from the get-go, and bless her, she was open to it as well. In the time we spent together, I made love to her hair a LOT. Sometimes I'd ask. Sometimes she'd offer it. Sometimes we'd be lying in bed; sometimes she was simply sitting in front of me. She got used to just relaxing and feeling the motion in her roots, which she apparently really liked. I got practiced in my aim, shooting right at the center of her scalp so that no one could even tell afterward what we'd just done - no liquid in sight.
Alas, such is a couple decades ago at this point. I've yet to have a similar relationship since. Which is why I suppose I'm here, finally delurking. 'Sup, fellows of great taste.