Selena Gomez is confessing to a lie ... that she isn't bothered when people body-shame her, because it's actually a gut punch.
Selena says although she pretended not to be affected by social media posts zeroing in on her weight, she says behind closed doors she would cry her eyes out.
The "Only Murders in the Building" star had a reason ... "I was posting these things saying it doesn't bother me because I didn't want it to bother other people who were experiencing the same thing," adding, "Getting shamed for what they look like, who they are, who they love, I just think it's so unfair."
As you know, Selena was diagnosed in 2014 with lupus, which has various side effects including weight gain. She said, "I was being shamed for gaining weight because of my lupus."
Just last year, she went after body shamers ... saying being skinny isn't worth the hassle of denying yourself your favorite foods. The reason, she says -- "people bitch about [my weight] anyway." And then the zinger, "Bitch, I am perfect the way I am."