I don't think a man should feel any of those things because of a vibrator. Because guess what? Everyone masturbates. That's right, everyone. Sure there is like 2% of the population that doesn't, but the rest do. And what do people do when they masturbate? They do what feels good, and if a vibrator feels good then they do that.
So that would be like me getting jealous of my boyfriend's hand. I don't think it should be insulting at all because people aren't always in the mood for sex. Sometimes people are tired, sick, out of town, whatever... So if your partner is not in the mood for whatever reason and you are, why not go for it?
If it was dinner time and your partner wasn't hungry would you eat anyway? Sure you would, same principle with sex.
You can't compare a person to a sex toy, it's not even on the same level.