How would you respond to a friend, in front of you, telling a girl, "He was saying how fit/hot you are"?

Couldn't see this question asked elsewhere. What's a strong response to this? In my experience it leads to awkwardness and you, or whoever is supposed to have made the statement, being expected to make a response. I'd say it's worse when you aren't close with her because playing it off as a joke or whatever isn't so easy.