I slept with my ex’s brother 3 years ago and my friend who’s also my ex’s best friend told me that I was his first love and I broke his heart by sleeping with his brother when we weren’t together, then a week later he found someone else and we stopped talking completely. His best friend told that he lost most feelings when I slept with his brother and now he had no feelings at all since being with his new girlfriend. But whenever my ex sees me he stares and watches me, !!! NOT WITH A DIRTY LOOK!!! He will look over 50 times and when he gets caught he will get embarrassed and look away quickly, sideways, or the other side from me. And this has been happening since last year (the staring at me part) even after he gets caught, he will try and sneakily stare again.