Once we were trying to make babies, Lydia, Frank, Carl, and I continued to meet for breakfast and sex. But we stayed with our spouses rather than risk swaps, even with condoms. Lydia and I were careful when we got together. There wasn't any literature telling us whether a bisexual partner could get a girlfriend pregnant if a husband's sperm was still hanging out from the night before. We didn't want our fingers, tongues,...