It was a normal stay-at-home dad day for me. I was chatting with tall, thirty-something Dominique, broad-shouldered in a sundress, big hands like fluttering pigeons. She was paying her daughter’s college tuition by watching a pair of three-year-old twin boys whose parents sold antiques in the West Village. Dominique held my attention and that of a couple of moms—Juliet, a single bartender, and Sage, an erstwhile graphic designer whose husband renovated brownstones. They each had a toddler. As usual, I was the only dad in the park. But caregiver-ship trumped gender. I was, essentially, one of the gals . . .