Jealous Much?

The funny thing about being an ex is the jealousy that oozes out when she/he finally found out that someone else has interest in them... In the case of the dump-er, she/he can't be jealous to show what they let go. So, they hold it back and become spiteful and blow up to anyone who dares to say hello. Why should the dump-er feel jealous? Is she still in love with the dump-ee? What upsets the dump-er is how come the ex's ex suddenly has the time and starts commenting on everything?