confusing post, you think he's cheating, or something along those lines?
i've come across a couple spells that expose a cheater, or stops someone from cheating [though i doubt it would] but you should talk to him about it. spells could help the situation, but more often than not it'll hurt it. sit down and talk about it, and ask him if he's cheating. granted he'll probably dispute it, so go to a councilor or something, maybe a truth spell, but in a situation like this your heart is clouding your mind, so you might do something you'll later regret, so just talk to him, and if you believe he's lying to you decide for yourself if he's worth it.