When I was in my 20s, an older lover introduced me to having my nipples manipulated to increase my pleasure. The first time she did it, I was fucking her and she wet her thumbs and forefingers and began rolling my nipples. The pleasure was intense and made my orgasm that much harder.
Another partner thought of draping herself over me from behind, playing with one nipple as she jacked me off, usually whispering into my ear things such as 'What's all that sighing and heavy breathing about, hmm?' and 'Is that good, baby? Want Mama to keep it up?' and sometimes she would kiss me, her tongue in my mouth as she was rolling my nipple and jacking me off, the combination of sensations always causing me to come almost explosively.
Finally, another partner had me play with my nipple and jack myself off while she watched, usually wearing something provocative and telling me I couldn't touch her yet, and to remember what she was wearing the next time I jacked off. She called me from work once while I was home with a cold. She had me jack off while we were on the phone, while she was telling me about the dress she was wearing, and how it fit so tightly around her tits and ass, and about how short it was, and she asked me if I was playing with my nipple like I was supposed to. I still enjoy nipple play, and any woman who plays with my nipples usually gets me very hot, making our session that much more exciting.
The only black woman I ever fucked kept up an ongoing flirtation, culminating one day with her reaching out, and touching one of my nipples, meant to be a tease. The surprised look on her face when she saw me close my eyes and gasp told her she had hit an 'on' switch. 'Goodness, child! Did I do that?' Our first fuck session took place that night, with her playing with my nipples, as I played with her gorgeous tits and nipples. The fucking was exquisite.