I know guys who purposely do things to get a reaction out of some females.
Some woman will shoot straight into their trap and go off and be mad. They are set in the trap. Then you have some females they will pretend not to care and don't even acknowledge what it is they had done to make a female jealous.

which is better ignore or react

If you know that is what they are doing, dont react. Why would you. He could be doing it to get a reaction out of you.
It all sounds pretty immature.

I do agree with you . Many do it for that reason.