2. "Helen's pregnant… Shhhh."
Remember on Sex and the City when Carrie tells Aidan that Miranda's pregnant but that he can't tell Steve? Remember how upset Aidan was to hear the incriminating news? Your boyfriend doesn't want to hear information that could get him into trouble. And even if he does want to hear it, he really shouldn't. Don't burden him with someone else's secret. And besides, if he does spill the beans, your friend is going to be mad at you, not him.
Along the same lines, he doesn't want to hear about your friend's yeast infections, her irregular periods or her IBS. It's bad enough he has to hear about yours.
[Sex and the City via @bananafanafo]