Shirtless domino effect

Hey bros,
So I love being shirtless. But I’ve been wondering, if I’m either with another guy friend, or around a group of all just guys and no has taken their shirt off yet, how should I go about starting the train? Like is there a right moment to take it off? Should I ask permission or just go for it? Does it have to be a sporty event or can it be anytime just as long as no girls are around?
Anyone have an answer or a story with this answer? I’d like to know your thoughts!