Exh used to do this. Go through my phone and then drop exact wording I had used into conversation. He was abusive and he would deny he had been through my phone. I liked to leave me wondering if he had or hadn't.
I had absolutely nothing to hide. But realising you have absolutely no privacy feels very exposing. It's part of the abuse to make sure you know they have the power and they know everything so you better not step out of line. Not affairs, but anything at all. Watching what you message to anyone, female friends, family etc I had no privacy at all. Not with female friends anyone.
It amazes me how many people defend behaviour like this. Usually because they want full access to their partners phone or because they also sneak through their partners phone.
Exh uses to do things like Park outside my work, because he was convinced I was snraking out during the day to have set with people. He ended up terrifying someone her worked with, with a very similar car to me. He chased he down the ring road flashing his lights and beeping his horn. When he got alongside her, he realised it wasn't her. She recognised him. It was awful. It was escalation because he never found anything on my phone to prove anything, because it wasn't happening.
My life was made miserable when a colleague messaged me, one morning, to ask which training session I was in that day. We were both managers and he wanted to make sure there was cover in office. Thats all it said 'what time are you in training? I am just making sure we have a management cover'. That misery lasted 2 weeks.
Op absolutely shouldn't be ditching her friends, male or female because he is insecure. Just because you are insecure, it doesn't mean you behaviour is OK or that you are right to do what you are doing.
When he started this behaviour of course i reassured him. I even gave him access to my phone. I never deleted anything. But he continued to go behind my back.
Its not OK. And it does often form part of abuse and control.