Why do guys like it when I pretend not to care?

This question is to the guys and if girls want to reply thats fine but heres what happened I was talking to my ex and well I told him to call me he was like I dont know but when I said fine I dont care if you call or not and then hes all like ill call...

you tommorow at eight its been proven when I treat a guy indifferent hes all on me when I show interest their there but they take advantage why?

maybe they like the fact that you leave them hangin wanting to go out and get you or look for you..but if you show intrest all the time that means that they can come talk to you for flirt with you whenever they feel like it which takes the fun out of it..I guess he also wants to keep in touch with you he doesnt want to fully lose you so when you show him that side he'll change his mind because he doesnt really want you to not care..I dont know if I answered your question correctly..hopefullly I helped in some way though XD