Has your physical relationship changed? Does he want to spend time with you? Is he out late? Do you ever check his phone? It may be an invasion of privacy, but if you really think that he is cheating, personally, I would be asking people about him and checking his messages. But, if you really have no reason to think that accept that he hardly spends time with you, he might just be busy. It would be bad if you start accusing him or investigating, if you are wrong. Make sure that you really have an excuse to do it before making a move. If you are wrong he will not trust you anymore if he finds out, and guys don't like having an overly jealous girlfriend. I hope you get the answers that you need.. And I hope it is the answer you want. Good luck!
