In hindsight, the signs of cheating are often pretty easy to spot. Looking back, it was probably a bit weird that your significant other was suddenly super vague about their weekend whereabouts. And what screams cheater louder than a partner quickly switching tabs whenever you walk by their laptop?

But there’s a reason so many of us fall for flimsy excuses and look past suspicious behaviour, Rachel Sussman, LCSW, a New York City–based therapist and the author of The Breakup Bible: The Smart Woman’s Guide to Healing from a Breakup or Divorce, tells SELF. (And no, it’s not because you’re a sucker.)

“The status quo feels very safe, and most people don’t want to acknowledge that the person they’ve trusted, loved, and spent so much time with is betraying them,” Sussman says. Facing the fact that you may have an unfaithful partner can be difficult for a variety of reasons.

For example, many people turn a blind eye out of fear that cheating signals the end of their love and sex life as they knew it. Others ignore common signs because they’ve convinced themselves it was just a “one-time thing” or that “it’s all in their head.”

Listening to your gut isn’t so simple, especially if you’re madly in love (or firmly in denial). However, if something feels off, it’s important to explore that uneasiness, since it could be a sign of infidelity and save you time (and heartbreak) in the long run. “Your instincts can help you recognize the signs of cheating, but instincts are usually refined by life experience,” Nikquan Lewis, MS, LMFT, sex therapist at Intimate Connections in Katy, Texas, tells SELF.

That’s why “it’s important to pay attention to those physical, mental, and emotional cues that your body gives when you’re uncomfortable,” Lewis says. “That’s how you learn to trust yourself: By being mindful and aware of what you’re experiencing.”

And don’t just take that advice from the relationship experts, but also from nine people who lived—and learned—from being betrayed by a cheating partner. Here, they share with SELF some of the subtle signs (and dead giveaways) of infidelity they wish they’d heeded.

He stopped wanting to have sex with me out of nowhere.

It was our senior year on spring break. I went on a friends’ trip to Punta Cana, and he went to Spain with his buddies. We hadn’t seen each other in almost two weeks and I was really excited to spend time with him. When we finally returned to school, we hung out every night, but he weirdly kept going to bed unusually early—which is fine, but he would typically be all over me after being apart for so long. I didn’t want to be reading into it, but as it turns out, one of the times he cheated was while he was away in Spain, which probably explains the sudden change in behaviour. —S

She was weirdly overprotective of her phone.

My ex, who cheated, was constantly changing her passcodes (which I found a bit odd) and would frequently make excuses for why we couldn’t use her cell phone to play music or pull up directions when we were driving in the car. I also noticed that her phone was always facing down on the table, and her facial expression and body language changed, as if she was panicked, whenever I held or used it on the few occasions she allowed it. —J

He always accused me of cheating.

We dated for almost three years, and he was constantly paranoid about the possibility of me cheating on him, even though I never did anything to make him distrust me. For example, he made me unfollow all of my exes on Instagram and he hated it when I hung out with my male friends—a major red flag. He would constantly gaslight me until I believed that I should cut out all other men from my life out of respect for him. Well, he ended up cheating on me for six months.

Looking back, I see that he was projecting his insecurity onto me. I think his low self-esteem made him scared of losing me to other men, and at the same time, having another woman’s attention made him feel better about himself. —K

He made me feel really guilty even for asking if he cheated.

Not only did I find out he cheated on me on the night he said he loved me for the first time, but when I asked him about it, he made me feel like I was crazy for not believing him. He said things like, “You’re really going to trust people you don’t know over me?”—even though I had multiple friends and classmates repeatedly telling me he was unfaithful.

Over the next few days, he started treating me like shit. He stopped answering my text messages and wouldn’t hang out with me, so I broke up with him. He talked crap about me after our breakup, which I never understood, but later I got confirmation that not only did he cheat with one girl that night—but three! So moral of the story: You’re probably not paranoid. —M

All of a sudden, he started overwhelming me with gifts.

As boyfriends tend to do, my ex gave me sweet presents, but there would be periods of time when he would go a bit overboard. He would take me out for expensive dinners, buy my favourite flowers, and even go out of his way to bring me lunch to work. Instead of these gestures making me happy, the only emotion I felt in the pit of my stomach was sickness. I knew something was wrong. It was as if he was overcompensating for something.

Eventually, his ex reached out to me and asked if we were dating. Turns out, he was hooking up with her behind my back and told her we had broken up (which was a lie). My initial suspicions were confirmed and all of the other warning signs were there, including the fact that he constantly checked his phone and turned it away when I would try and see what he was doing. He ended up getting back together with his ex, with no remorse. —S

He surrounded himself with people who condoned cheating.

Around the time I discovered my former boyfriend was unfaithful, he had a best friend who was cheating on his fiancé. My ex and two of his other friends (who both knew about it) would cover up for this guy and never say anything because it “wasn’t their place.” Personally, I would want to know if my soon-to-be husband had been unfaithful, and it rubbed me the wrong way that my boyfriend was seemingly okay with it.

Another similar concern: He would listen to Instagram reels and YouTube videos of problematic influencers who justified infidelity and encouraged men to cheat. Obviously, I would get annoyed, and my boyfriend would say something like, “No, it’s edited to make it seem like he’s a bad guy.” When I suggested other less misogynistic, speakers to get inspiration from, he would refuse my recommendations and wasn’t even willing to hear me out. —A

She was hesitant to acknowledge our relationship online.

My ex was very active on Snapchat and Instagram, but clearly made an effort to make sure I didn’t show up in her stories or posts. It wasn’t that being included in her social media was something I cared about, per se. It was just the fact that although she posted selfies with her friends almost daily, she would never point the camera at me.

I later found out that she was still messaging and flirting with other guys, which explained why she avoided posting about me online. However, I was deep in denial then, so I still didn’t see the cheating coming until after it already happened. —W

He made me feel uncomfortable when he’d hang out with his best friend.

I was romantically involved with my roommate during my senior year of college and despite everything—and everyone—telling me that he was bad news, I convinced myself that my anxiety was playing tricks on me. Whenever I saw him speaking with the girl I later found out he was having an emotional affair with (and whom I had been worried about for months prior to him leaving me for her), I always felt like I was intruding or the odd one out, despite us being together for nearly a year. I avoided all the telltale signs yet knew in my heart that he was emotionally invested in someone else. My advice: If someone doesn’t validate your concerns, trust that gut feeling and move forward accordingly. —B

They would never pick up my phone calls on the first ring.

Technically, I was the other woman, but I had no idea that my partner in college had a whole-ass girlfriend at the same university as us. Whenever I spontaneously tried to FaceTime, they wouldn’t pick up immediately. They’d call back ten minutes or even an hour later with a poor excuse like, “Sorry, I’m at the gym,” even though I know they didn’t work out.

When we were about to meet up in person, they’d say stuff like, “Wait, actually, I have to do something,” then change their mind a few minutes later with something like, “No, let’s meet.” I later found out that I was being cheated on with the girl who I thought was their ex. —E