I'll admit, DH is one of those guys who goes without a shirt often. I always gripe at him, but he is so hot natured and he would rather go without a shirt than wear a soaking wet one.
In his defense, he is from a beach town and life is pretty casual there. But I still get super embarrassed!
I don't think I've ever seen DH inside or outside without a shirt unless he was in the pool or ocean. DS hasn't gone topless outdoors since he was about 10.
Pool or beach. He wears a shirt to sleep and to mow the lawn. He's in really good shape so it's just his preference. I think it's pretty snarky to mock your shirtless neighbors doing their lawns. It's hot. Whatever.
I do not trust dudes who feel the need to take their shirts off anywhere other than the beach or the pool, or their own backyard after they finish mowing the lawn or something. It's never hot enough that someone walking down the street needs to take their shirt off. It just isn't.