He's your ex, you two got last week into a heavy argument and it ended with you two both saying that you're breaking up with each other. Everyone in the batfamily knows what happened.

Batman knows also you two had been dating for more then a year. He asked you two to go on a mission with each other. So here you two are, at a Friday evening, on a mission to figure out what the Penguin's doing "We're doing my plan" Jason eventually said in a cold voice, clearly not pleased about this