I went to Herring Cove in Provincetown yesterday with my (adult) son. I’ve always really enjoyed this beach despite its very coarse sand. If you walk 10 minutes to the left from the far end of the parking lot, the crowds thin out and, for a many years, you’d see people sunning nude or topless. Nude is not strictly legal and a few years back some of the locals started warning me that rangers were asking fully nude people to cover up. (This is one of the reasons I decided to start wearing thongs, which are legal. My GF still goes topless, and that’s never been an issue here.)
There are fewer rangers this year and we only had to walk five minutes before we started seeing some nude men. We walked a bit farther, set up a beach umbrella, and I was arguably overdressed in my usual Skinz M67, what with having several nude guys to our left and our right. We were there for a few hours; a couple of pairs of people walking their dogs stopped to talk with me, all good.
While walking back to the car, I didn’t cover up with my board shorts to see if anybody in the more crowded area right by the entrance would care. Nope, not a peep or a second look (AFAICT) from anyone. No reaction from anyone driving by in the parking lot or at the showers, either.
TL;DR – Herring Cove is good to go. 