The cake is a lie

its never okay to cheat. no one likes to be cheated. but for this question since it has the '(if ever)' i guess its okay if the person you are cheating to knows that you're cheating on him/her and doesn't care about it. maybe because he/she is also cheating on you so he thinks its fair enough or you're relationship is not a serious one. but if you're in a serious relationship and respect and love that person, don't even think about cheating.