Pygmalion and Galatea
Pygmalion didn't like women, and he avoided them at all costs. He was a sculptor, and one day he sculpted the perfect woman. She was beautiful, and he took care of the statue. One day he went to the temple and was praying to Venus on her feast day and saw a candle leap three times. He went back to his home to find the goddess had blessed him by bringing to life the woman, Galatea. She had awoken from her statue state and was alive.
Endymion was most likely a shepherd and was a beautiful mortal. The moon goddess Selene fell in love with him and cast into a deep sleep for eternity so she could always see him, and he is immortal now, but always sleeping.
Ceyx and Alcyone
Ceyx had to leave for a voyage and he drowned while at sea. His wife Alcyone was still praying to Juno for him and Juno felt pity, so she sent her messenger Iris to go tell the God of Sleep to let her know Ceyx is dead. He sends his son Morpheus. Morpheus appears to Alcyone in her sleep as a dead Ceyx and tells her he has drowned. She decides the next day she won't try to live and goes to the ocean, where she sees her husbands body floating farther out. She swims to him and turns into a bird and finds him in the bird form as well. They live happily together as birds after this.
Pyramus and Thisbe
Pyramus' and Thisbe's parents hated each other, so they talked through a hole in the wall. They planned to marry and meet by a mulberry bush. She arrived first and saw a lion with a bloody mouth and ran, dropping her shawl. When Pyramus came he saw the lion chewing on her shawl with a bloody mouth, and he thought it had eaten her. He knew if he would have been on time she would've lived, so he took his own life by the mulberry bush. She came back and realized what had happened and took her life as well w/ the same sword. The god's decided to make the mulberry berries red to forever commemorate the blood the young lovers shed for each other.
Orpheus and Eurydice
Orpheus was a musician. He fell in love with Eurydice and they were married. But a few days after they married, she was bit by a serpent and died. She went to the Underworld and Orpheus came to Hades and begged to Hades to let him take her out. Hades agreed on one condition: He must not look back to her until they arrive back on Earth. He finds Eurydice and leads her all the way out, and once he is on Earth, he turns around. She had not stepped all the way out of the Underworld however, and fell back in, wishing him farewell.
Cupid and Psyche
Psyche was very beautiful and all the men started adoring her instead of Venus. Venus told her son, Cupid, to shoot an arrow down at her and make Psyche fall in love with an ugly beast so the men will worship her again. However, when Cupid saw her he fell in love. She was sent to the top of a mountain one day, and a wind blew her to a house with riches. A voice she could not see told her these were her riches. She was considered married then to this voice, who only came at night. One time her sisters came and were jealous so they told her that he was probably an ugly beast and wanted to kill her. So they made a plan together for Psyche to go and get a lantern and when she sees him to knife him. She saw him and realized he was the god of love and gasped, dropping hot wax on him. He woke up and said he couldn't live in a house with no trust so he left. Psyche searched for him for a long time and did impossible tasks for his mother and finally he healed and found her sleeping and he married her officially and Venus wasn't jealous anymore because Psyche became a goddess.
Baucis and Philemon
Jupiter and Mercury went in disguise as beggars to a small town. They went from house to house, asking for help. No one did except an old couple, Baucis and Philemon. They served the "beggars" and after the fact realized they were gods, so they tried to find better food. Jupiter and Mercury admitted who they were however, and showed them outside, where everything had been washed away. They promised to grant any wishes the old pair requested. All they asked for was to die at the same time and be able to be a priest and priestess to the gods.They were granted their wishes and years after they started growing leaves and turned into two trees with one trunk.
Daphne and Apollo
Daphne was a huntress and wanted to be a virgin. One day she was in the woods and Apollo saw her and chased her, trying to pursue her. She called out to her father who turned her into a tree.
Alpheus and Arethusa
Arethusa wanted to be like Artemis and stay a virgin. One day she was bathing in the woods and heard a voice, so she ran. She realized Alpheus was behind her, trying to pursue her. He chased after her and caught her, so she prayed to Artemis. The goddess took pity on her and turned her into a spring.