Ah yes, the good old game of jealousy. You showed no interest in spending time with him, no interest in hearing his compliments and jokes, and there you are, having a blast with other guys, laughing at their jokes and blushing at their comments.
I think there’s no need to describe how utterly miserable he will feel when you do this.
Seeing you having fun with other guys will make him lose his mind for you and he will be determined to make you realize that he is the one you should be paying attention to.
But, be careful not to appear too flirty, just enough to light a spark of jealousy in him.
He will get the competition he needs and will have the chance to prove once more how much of an amazing guy he is (not).