My 10 year older brother in law 
commented on my photo via private message on Instagram, I didn’t feel I did something wrong but when reading the messages I can’t help but feel a bit guilty. I showed to my husband who said this is strike 1 so he will see how it develops but he is more worried if my sister gets to see this that she will simply quit my brother in law. What shall I
Of all the things wrong with this, what sticks out to me how he seemed to be offended when you put down your boundaries. I feel sorry for your sister and i would share this with her. If he behaves like this with his own family, it doesn’t bode well outside of it. Yeah, perhaps replying wasn’t the best idea but i cannot put myself in your position vis-a-vis your state of mind at the time but it doesn’t take away the lack of appropriateness of his comments.