Is this cheating?

My friend had become friends with this guy online and didn't tell her bf at first. The guy friend also is in a relationship and the both of them were planning a double date. My friend's boyfriend found out by searching her phone when she was asleep and he got mad. I have read the conversation and I don't think there was anything said that was flirty but she should've told him sooner about the friendship. She told me that she wanted to but was scared of her bfs reaction because he is not good at reacting to her having guy mates or colleagues or even talking to a guy in public for a brief moment. He told her to block and delete him from social media and she thinks he's being controlling. He told me that he just feels hurt and lied to. Do you think she cheated?