I never thought that my nipples were all that sensitive, and they never really added to my arousal. Sure, my wife would half-heartedly rub them sometimes, but she'd lose interest in playing with them way too soon (as she did with everything sexual).
But then I entered the world of occasional BDSM play with other men, and that changed things for me. I remember one of the first times I was in bondage (stripped to a jockstrap, standing spread-eagle with arms and ankles in spreader bars), one of the guys that started to spank and generally play with me said that a lot of guys like their nipples to be played with. I think my answer to him was "that wasn't really my thing." I was wrong. He (and others) started to rub, squeeze and generally play with my nipples which immediately caused me to get rock hard (well, OK, I was probably already rock hard but the nipple play definitely added to it).
Since then I've played one-on-one with a few Doms, and they all love to torture my nipples. They'll squeeze mine and use clothes pins and nipple clamps on them, and then enjoy the reaction from my hard cock.
And they all like to have their nipples "serviced" too. There's nothing quite like being stripped, collared and blindfolded with my ankles cuffed together and my wrists cuffed behind my back, then pulled into my Dom's chest and told to suck his nipples. I even had a session where I was one of two subs and our Dom had both of us working on is nipples at the same time, one on each side. On that occasion we also took turns with one of us sucking his nipples and the other kneeling in front of him working on his cock! Such fun.
I can't wait for this virus to be over.