did I do the wrong ?

So tell me if I did wrong . Last night I decided to follow my boyfriends ex gf through Instagram but through my moms ig, just to be curious. I wasn't going to message her or anything like that. But my bf found out about it because his sister told him that she called her & said pretty much I was trying to get in contact with her. Which wasn't the case no my bf broke up with me did I do wrong ?