is this cheating?

im on the fence about this. my ex had this friend who was a girl and i didnt have a problem with them being friends. but they did cuddle and hold hands and tease each other and they talked more than me and him did. also he told her a lot of stuff that he wouldnt tell me and i had to find out from her. they didnt have sex but she did send him pictures of herself almost naked

i broke up with him for other reasons but this has always kind of bothered me.