Trust your gut, but don't assume
If you feel strongly that your partner is cheating on you, trust your instincts; our intuition often knows more than we give it credit for. That being said, you shouldn’t immediately confront your significant other with nothing more than a gut feeling. Unfounded accusations can only damage your relationship, especially if it turns out you were wrong, as it shows a lack of trust that can hurt your partner as well as yourself.
When you suspect an affair, first, analyze why you believe this. What behaviors have you noticed in your partner that are odd? Do you have any evidence to prove it? Are you simply afraid of losing them and turning that fear into a false belief?
It helps to write down everything that’s bothering you, both internal and external. Once you’ve calmly and rationally analyzed the situation, then you can consider your next step, whether it’s searching for more evidence of infidelity or approaching your partner with your concerns. Just be sure not to act out of pure emotion.