I'm going to cancel the plans with him.
It seems like you are very attracted to him actually.
Well he is bad for me. He is a pretty big liar and a jerk as well.
If that's true, then you should tell him that. Canceling plans won't solve your problem.
I don't have time for this.
If you feel this way about your partner than you need to talk to him. The only way to fix things in a relationship are to work on them, and you can not work on them if your partner does not know that it is an issue.