It's sad that already at this point in life many people, females and male, already see the opposite sex as a danger point in some aspect. Someone who's just going to cheat on them at the end of the day.
You just need to find the right person. You will be hurt no doubt in the process, and sadly there are people out there who just don't feel that cheating is a bad thing. It's sad that society just can't respect the fact people hurt.
Personal I find cheating, low, distasteful and a fact that they're shallow, two faced, insecure *****s. Personal opinion of course. If you're not happy with your partner, tell them and move on. Don't put them through the pain of finding out their partner is cheating on them.