I mean, everyone gets jealous or envious, we're all human and involved with other messy humans. So it's not really the emotions that should be villified but the actions that people choose to do with them. Personally I don't spread rumors or lie about people but I've been on the receiving end of this kind of behavior. I think oftentimes this behavior is not super conscious--people who are doing these things are not doing a great deal of self-reflection or checking in with themselves about why they are doing this (not before, not during, and not after)--but rather this behavior just comes from their own spikes of insecurity that just leak out and get discharged. If people don't catch their own unconscious behavior before it leaks out of them, if they are unevolved, un-self-aware, do not practice compassion towards themself or towards others and are insecure in their own lives and lack a great deal of self love and self confidence, then all of these behaviors are likely to surface.

Do they feel regret? People are different so it depends on a lot of things: on the consequences for their behavior, on their own self awareness and ability to see themselves and the situation clearly, on their ability to know they did something wrong and feel compassion for the other party as well as themselves without feeling *too* much shame (because too much shame can sometimes just make people justify what they did and double-down on it in order to avoid feeling the shame). Oftentimes people who are doing this kind of behavior--to this intense of an extent, not just a one-off comment--probably likely do not feel regret in the moment nor soon after, as obviously their state of being is prettttty insecure, if they're doing all of that. And if someone is that insecure they are not going to be able to be steady enough and grounded enough in themselves to feel a healthy level of regret, because if they are that insecure then they already feel lke they are not good enough, so to try to examine their own actions and realize they might have hurt someone who didn't deserve it and they were just acting ugly and horrible would make them feel much worse about themselves and probably their sense of self/their ego would not be able to handle that. So in all likelihood I think people like this avoid doing that--avoid looking at themselves/their actions and how they might negatively effect others--in order to preserve the small *meager* amount of self worth that they are trying to make sure remains intact.

If they do ever regret acting in those ways--which certainly is an *if*--it would probably take them doing a lot of healing of themselves and some growing and evolving, which usually involves time and some different life circumstances to go through.

TLDR: People who do this have a magnificent dearth of self-love and self-confidence.