Comment by 29athrowaway

Some toxic people can be good at provocation, victimization and distorting situations. An attempt to improve things over a cup of coffee can be distorted as rumors, slander, harassment, intimidation, threats, etc.

A person that reached adulthood while being toxic throughout their life is probably competent at it at this point. While you were focused in acquiring your skills, they were probably getting better at being toxic. So you are probably not prepared for a direct confrontation with a veteran sabotaging jerk. Do not play a game you have never practiced as the away team because you are probably not going to win.

The more you have advanced your career, the more you have to lose while engaging someone. And in this case you have not much to win, against a person that has less than you to lose. Just using up your time and distracting you from your job is a win for a saboteur.

Anything you say can be held against you, so unless you've talked to a workplace attorney better stay out of it. If the situation is affecting you psychologically then engaging the person can affect you even more. Seek therapy if that helps, or channel your frustration through physical activity.

The best you can do is to limit your interactions to the professional level, and limit the topics to what he is working on. Everything else is your business and not his and you can seek additional collaboration at your discretion.