For years, Evan Sterrett’s relationship with his boyfriend had become “reruns of the same drama.” Evan wanted space; his boyfriend wanted commitment. But one summer, their relationship received a guest star — a third partner who resuscitated their joie de vivre.Today, we hear Evan’s story about navigating the complex geometry of throuplehood. Then, we meet Samatra and April Doyle. They don’t live together and don’t co-parent, but they are married and intend to be together forever.