"Well, yes if you would have me over." This was Rude's apartment and not the Shinra Building, after all. "I'm going to have more meetings in Edge in the future so we'll just happen to come by here on our way back."

If Rude wanted to keep this secret then Rufus would find ways to make sure they weren't caught. Perhaps the others knew and just hadn't said anything but Rufus wouldn't be the one to tell.