My bf and his lies

My bf said he deactivated his Instagram because I didn’t feel comfortable with him having one after we had certain problems with it. His account is on private. I can still send him a request to follow. He said he doesn’t even have the app or anything, yet I saw he gained one more follower. And in order to do that he had to accept since he’s private....so wtf he lying to me? How do I tell him?