One variant tells that Achilles fell in love with Polyxena, Priam and Hecuba's daughter, having seen her with her brother Troilus, and rather than ask for gold in exchange for Hector's body, he asked for her hand in marriage. In this version, it is she who finds out from the dazzled Achilles that he is vulnerable on his heel, tells her parents, and she lures Achilles to a temple of Apollo so that Paris can kill him. Polyxena is known in every version as the maiden who was sacrificed on Achilles' graves so that the Greeks could raise a wind to get home. Oh, well, the Trojan War got under way with the murder of Iphigenia and ends with the killing of Polyxena. Bad days to be a virgin. Look what happened to Cassandra.
I have not thought much of Theseus' story but he had a relationship in some of the myths with the queen of the Amazons, Hippolyta. They met when Theseus helped Heracles obtain the girdle of the queen as part of his twelve labors. Some versions say it was her sister that he was betrothed to. They had a son Hippolytus who lived with his father after Theseus cast his mother aside for the sister of Ariadne, Phaedra. Theseus was a dog. He was punished when his wife Phaedra fell in love with his son, Hippolytus, and killed herself when he would not return her love.
Many of these stories can be found in Ovid's Metamorphoses but some of the alternate versions can be found in the book of Apollodorus, or Pseudo-Apollodorus if you prefer, called the Bibliotheca or Library. Here is a link to a translation by James George Frazer who wrote The Golden Bough. Apollodorus disagrees with Homer in some of the details of the Trojan War and writes that Homer got it wrong. So many myths are crisscrossing and doubling back. I need to figure out what it all means so I can write an amazing paper about it.