My popularity at office

A and S are my colleagues. S just came on-board the project and A was expected to ramp her up. Today, when they were having some discussion, I informed A about S being unhappy with his mentoring. Ofcourse, I said this in a humourous vein. We had a laugh at this. Later when A left, I had the following conversation with S.

S: Why did you lie? He would think bad about me.
Me: I know him. He will not bother about this.
S: Does he know you well?
Me: Yes.
S: Then, it is fine. He will not think much about what you said.

So much for my popularity at office.