why was Mallory so mad at Sam?
In the episode "Galileo" Mallory meets Sam and says she was mad at Sam because she saw the picture of Sam with the call girl.
However, if you recall, Mallory first met Sam in the White House and Sam mentions that he just slept with a call girl. Then the following weeks when Josh takes Charlie out for drinks she tags along and says Josh needs to bring Sam because she wants to talk to Sam some more. So although she knows Sam has slept with a call girl she seems to have no problem spending time with Sam because he slept with a call girl.
So why when he simply has a picture taken with a call girl is she very upset about it?