1. He’s been hitting the gym more. Or wearing a new cologne. Or dressing much nicer than his usual jeans and a t-shirt. The point is, he hasn’t put this much effort into his appearance since the two of you first started dating. He’s clearly trying to look good — and you aren’t convinced it’s for you.

2. He’s been bringing his phone into the bathroom and shower with him. If he never leaves you alone with his phone, puts a passcode on the screen, and switches it to airplane mode whenever he shows you videos, then something fishy is going on. He’s texting someone he doesn’t want you to know about — or has downloaded a dating app he doesn’t want you to see.

3. He’s suddenly obsessed with social media. Everybody knows the main reason you post cute selfies on your Instagram story is to impress your crush. If your person has never really been a fan of social media but is now posting shirtless pictures of themselves working out in the gym all the time, they might be trying to catch someone else’s eye.

4. He turns off his location — and has been using cash more often than his card. If you’re already living together and sharing mail, then he probably won’t want any jewelry he buys for another woman or dinners they eat to show up on his credit card. It’s safer for him to use cash. That way you can’t trace anything sketchy back to him.

5. He’s been showering the second he gets home. He won’t hug you, won’t kiss you, won’t go anywhere near you until he showers. This might have to do with the fact he doesn’t want you smelling another woman’s perfume on him. Or worse, smelling the scent of sex on him. He would rather clean himself up before getting cozy with you.

6. He’s been coming home later and later. For some unexplained reason, his boss keeps asking him to work overtime. You’re never sure when he’s going to be home for dinner anymore, because he’s always staying late at the office. He has canceled entire date nights because he was working. Or was he…?

7. He’s been uninterested in sex lately. If he’s involved with someone else, then he might be getting his fantasies fulfilled outside of the home and will stop bugging you for sex. However, this could swing the completely opposite way. He could feel like hot stuff now that he’s cheating (or feel guilty about cheating) and want to have sex with you more often than ever. Basically, if there’s a big shift in his libido, you should be concerned.

8. He consistently leaves out details. If he ‘forgets’ to mention who went out with him for drinks after work or who has been texting him at all hours of the night, it’s a red flag. He didn’t actually forget. He just didn’t want to actively lie to you, so he purposely didn’t tell you.

9. He accuses you of cheating on him. Now that he’s cheating, he’s become paranoid. He thinks everyone is as unfaithful as him. That’s why he keeps accusing you of being the cheater even though you’ve done nothing wrong.