Michael and Patricia meet in an unusual way - while he is on a date and is trying to retrieve his date's car keys from a fountain. When Michael's date abandons him, he hangs out with Patricia and these two nice young people soon find themselves falling in love. They decide to wed and hold the ceremony in Canada, where Michael's family lives. Patricia's parents, who have been on a lengthy cruise and have never met Michael, cannot attend, but they meet their new daughter-in-law soon afterward. While reviewing pictures from the wedding, Michael's mother is shocked to discover that she knows Patricia's father. Even more shocking is the revelation that Patricia's father is also Michael's father, the result of a one-night stand many years before, and that the happily married couple are therefore half-siblings. To make matters worse, it turns out that Patricia is pregnant. The rest of Bittersweet Love is taken up with Michael and Patricia deciding what they should do about this situation, as well as with reactions and advice from their family members.