[¯|_(ツ)_|¯]

Hey,

I'm sorry to hear that you are going through this!

Everyone has the right to have friends no matter what their gender is, but I can also see where you would be upset by it. It seems suspicious to me that he deleted all the messages when you wanted to look at his phone.

I know you've tried talking to him in the past, but I would try to have a full-out conversation with him. Sit him down on a day when he is in a relatively good mood. Use "I statements" instead of "you statements." For example, don't say "you make me feel angry/hurt/etc." You can say "I feel uncomfortable/hurt/other emotion here when you hang out with other girls because (reason here)." You can also mention that you do not feel heard or communicated with.

Are there any possible solutions you can think of that will make everyone involved happy? For example, do you think he'd agree to you meeting some of the coworkers who he wants to hang out with just so you can get a feel for how they are?

Has he done anything in the past to cause you to distrust him? It may be a good idea to see where your feelings of distrust are coming from.