Is your guy hooking up at work?

Be a PresenceAnother cheat-proof-him strategy: Make sure everyone at his job knows he has a woman … and a kick-ass one at that. Be enthusiastic about joining him for work gatherings, whether it’s the company party, after-work beers, or his coworker’s birthday bash. Otherwise, a potential rival will assume she can steal your man because she doesn’t take your commitment seriously. In her mind, if the relationship is legit, you’d be there. By making your presence known, you’re marking your turf as well. “It humanizes you and gives you a face,” says Weil. “Not only will she realize you’re a real part of his life, but it will also make her feel guilty about trying to get it on with your guy once she’s socialized with you.”