No screwing on the space station. From The Telegraph:
"We are a group of professionals," said Alan Poindexter, a NASA commander, during a visit to Tokyo, when asked about the consequences if astronauts boldly went where no others have been.
"We treat each other with respect and we have a great working relationship. Personal relationships are not … an issue," said a serious-faced Mr Poindexter. "We don't have them and we won't."