if you're gonna cheat, dont get caught. You know what happens when u eat pasta everyday right? Eventually you'll get tired of it.
If I really thought I needed to fuck someone else, I'd break up with my current girlfriend. I wouldn't ever want to be cheated on, and I wouldn't do that to someone, especially someone who you presumably care about.
I get bored being stuck to one girl as well...or at least haven't found a girl that is worth being exclusive with her. So I just don't get into relationships and it works out for me. Stay single while you're still young