Should I give in to his demands?

My bf and I were kinda fooling around and my pants were down to my knees when his younger brother, he is 13 walked in on us. We quickly stopped when he walked in and realized my bf's parents came home. Later that day my bf's brother cornered me and told me he was going to tell his parents what he saw if I didn't let him see me completely naked. I don't want to get me or my bf in trouble so should I strip naked for him and let him look?