I think this really will depend on what social group you fall in with at university. In some groups there will always be people who are sleeping around, with each others, going out just to "pull" and generally experimenting sexually with one another. If thats not what you're after, you'd be well advised to stay away from these "partying" groups, or there will be a certain element of tempatation, and we are, after all, human, and fallible.
Most groups, at most uni's, are full of intelligent, mature people, who dont just casually sleep around for fun, and would have some level of loyalty to their partners. At the end of the day, if you are really in love, it's less likely you'll cheat.
But, Im not going to lie, it is a tempting place. You meet people who share your interests, can match you intellectually, and of all shapes sizes and appearances, so that its quite likely you'll bump into someone who seems very tempting indeed. In such a large crowd of people, there is going to be one or two that you will grow close to, fall for, or be tempted by.
I speak from experience. I went to uni but left a serious relationship behind. Even though I fell in with a group who dont randomly sleep around and get wasted, I did meet someone who was very close to being a soul mate to me. I couldnt help that I'd found someone ideal. I fell in love with him. But I loved my partner, I was loyal, and I didnt cheat. Ever. me and my partner split up in the end, but not because of cheating.
There's nothing you can do to stop a partner or yourself falling for someone, all you/they can do, is not cheat, or end their current relationship cleanly and fairly, rather than sneak around being deceitful. Loving someone, finding someone who is ideal is a risk of going to uni, but its also a risk of going out into the world. You or your partner will always be meeting new people and having chances to cheat. You cant change that, cant keep them or yourself away from the world. All you can do is be honest with one another if you do want to end thing and see someone else, communcate well and often, and place some faith in each other.
Uni is the place where a lot of people meet their life partners, so yes, people do cheat, break up, or get tempted. But at the end of the day, this is about believing in your partner, and trusting them to be loyal and love you. It's a scary thing, trust, but sometimes you have to do it, or you start harming the relationship.