Western cultures MF SEX seems to largely ignore the MALE nipples, while Asians, Indian, Blacks often enjoy this treasure! But Western GAYs do play with their nipples a lot. Those that don't are missing so much.
I was first introduced by my first girl friend who had super sensitive nipples. One day she asked to try mine and the rest is history! I love having my nipples licked, sucked, rubbed, kissed, etc. during foreplay and penetration.
A great technique is gently draw circles on the nipple with a finger and it stiffens super fast! Can switch around or rotate your fingers too. Works great on ladies too! Try it, you won't regret!!!