Nothing serious?

How can people kiss without being anything serious???? I really don't understand it.

My crush, whom we'll call "C," told me. I didn't confess my feelings towards "C" but he told me that after a past relationship he had, he wasn't looking for anything serious because in the end all the girls were going to cheat on him.

How can I tell him what I feel then? It doesn't matter if it's he likes me back or not, he wouldn't be open to the exclusivity that a relationship grants.