Tell her she can socialize with other men as long as ALL COMMUNICATION is SHARED with YOU.
You get CC'd on every email, accounts are not locked, etc.
And hit her with this :
Those who have nothing to hide, hide nothing.
Shirley Glass makes it VERY CLEAR in Not Just Friends, her landmark book on infidelity that ANY contact with "old flames" should be AVOIDED at ALL corners.
Your wife is straying sir and she's disrespecting you.
Cut this off at the knees or she will soon be in a hotel room with another man.