Help!! Nipple twiddling. Should I stop it?

I've been looking for insight on this all over the interwebs. Found zilch. Why is no one talking about this...Nipple Twiddling.

My baby breastfed for maybe 1 month and a half. He is soon to be 9 months, and tries to yank, squeeze, and twiddle my nipples.

I've been gently stopping him from doing it, but secretly feel guilty. He does it when he's stressed, sleepy, or just wants a good laugh.

Should I just let him twiddle for the time being? Any other mom, who's NOT breastfeeding, but baby wants to twiddle.

*he mostly just does it to me, not so much dad.