So, you are going to cheat on your significant other? why?

If you are going to cheat, dump the person you are currently with. It's not fair to him and if the situation was reversed, you wouldn't like it either. I won't really offer advice here because I don't truly support your plans.

If you are going to have an affair, you should figure out why you want to have an affair instead, what are you two as a couple doing wrong and what does the extra person doing right to entice you.