When i was 20 and had my first girlfriend we experimented on such things.

She often gave me hairjobs and then swingin her head around, so her hair would swing over my face.

She also let me cum in her hair twice while sitting in the bathtub.

Unfortunately her hair wasn't that long.(dark-blonde, straight, a bit past her shoulders.)

My fiance now has super thick and very ling, naturally waved, almost curled dark hair.(colored black).

It gets me super hard when she straightens it(which she does less i could hope for :(). Then it reaches almost her hips.

I enjoy her hair with pulling, wrapping my hand in it and smell it during sex.

Unfortunately didnt experience the things i did with my ex so far.

But one thing was really exciting for me. We did a "hairdresser" role play, where we had sex while she was straightening her hair.