Why is he mad when he cheated on me?

My boyfriend is mad at me because i got drunk and was bending over with thongs on, on facebook. And yes i made sure everyone could see it. He said that he should've chosen his baby mother instead of me because im a slut. ๐Ÿ˜‚. Why is mad when he's been cheating on me for 6 years now. And to top it off, he's telling people he's single. ๐Ÿ™ƒwhen he get caught, he tell them they knew we were together. Smh.
Why is he mad when he cheated on me?
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