This might have been a situation where the higher road was worth taking. As tempting as it is to twist the knife and be your fullest, pettiest self, there is a limit to how far one should go. It's easy to roll your eyes at the concept, but happiness is the best form of revenge at the end of the day. This mother of a now toddler realized that her ex-husband's 30th birthday was approaching. They hadn't seen each other in two years since their divorce was officially finalized. Their marriage fell…