After My Boyfriend's Brother Sent Me Pictures of His Abs

I'm in a long-distance relationship, and my boyfriend's brother and I go to the same university. He often sends me pictures of his abs with his hands. One time the photo angle was wrong. My face was ashen and I was ready to block him and then complain to my boyfriend. Unexpectedly, the next second, his voice popped up. It turned out that everything was a bet between him and my boyfriend. I saw their faces clearly. I don't want anyone like this.