I know this isn't the place to be asking this but what should i do if i think my partner i...

Piss in his cornflakes.

Unfortunately people cheat more often that not. You have to confront that person and tell them what you feel. A relationship is all about trust and feeling comfortable with eachother. You can decide to have an open relatinship in whích all parties will know about the others or you can break up. Once a cheater, always a cheater, so you can't trust if she/he tells you they won't do it again

dump them

milk him.
and then run for it.

kill him

Get some blackmail material and then send all their dark secrets to their mom. ╮(￣▽￣)╭

woah
real helpful we are

dump him, duh. but if you still love him, you can talk it out perhaps? get some closure of course when u break up

what you shouldnt do is snoop around in their stuff, cuz when they catch you thats gonna break a lot of trust more than needed atleast, but it really depends on the actions your partner has chosen to make you feel this way, because what if you're just overreacting? we may never know, confort him in a calm manner and talk things out with him, and if they admit they have, dump the fucker, but if they havent apologize and talk it out.

god i sound like i type up wikiahow's answers (￣∇￣")

1. Why do you think he is cheating?
2. Is it true that he is cheating?
3. Never make any decision with assumption.
4. Confront him with manner. Calm and mature.
5. If he denies then you could believe him
6. If you are still suspicious, then tell him
7. He should know you are unable to trust him
8. And if he was found out that is it.
9. Break up if he is cheating.
10. After listening to his reasoning.
11. It doesn't help anything, but I would listen anyways
12. Because clean break up is nice. I am a nice person after all
13. Fuck cheaters.