same and he's a guy; so being shirtless is relatively acceptablebut my imo it’s not really strange that he’s chilling shirtless in his own house
I personally wouldn't post something like that on the internet but my sister and I are super chill about being naked/in underwear around each other, I don't think it's that weird among siblings. You could argue it's different because we're both girls but still, I think it's fairly normal, posting it is what's strange to me but if he's okay with it, why not? And he's probably posted shirtless pictures of himself too