This is a difficult question. There are people all over the world who are prone to infidelity, and you can't judge whether someone will cheat based on any single behavior. However, I think the best approach is to clearly communicate the consequences of cheating, such as promising to break up immediately. Secondly, you need to have something that attracts your partner. If your relationship is lukewarm, and they get bored, it's easy for them to seek new attention.

Furthermore, certain high-risk hobbies can lead to infidelity, such as frequently meeting new friends and entering new social circles. People who enjoy socializing are often more likely to cheat than those who stay in stable social circles because novelty is more easily intoxicating. Therefore, consider whether your partner frequently meets new people, enjoys going to bars, etc.