gods falling for mortals makes me think of Dionysus and Ariadne... who, incidentally, I named my Lavellan after. Like all myths there are about nine billion versions of it, but the one I heard growing up hits me right in the feeeeels.
Ariadne was a princess of Crete, who fell in love with Athenian prince Theseus who was being sent as a tribute to her kingdom... he's supposed to get his butt sacrificed to the Minotaur, Ariadne's monstrous half-brother, but when Theseus is sent to the Labyrinth where the Minotaur dwells, Ariadne sneaks him a ball of thread (lol Merrill much?) and he's able to kill the beastie and find his way out of the maze without starving to death. He promises to marry her, and on the way back to his kingdom they stop on an island and party all night... aaand Ariadne wakes up in the morning to find Theseus has abandoned her and eloped with her sister. WHAT A DOUCHE.
In her despair, she tries to end her life, crying out to the heavens- after all she did, even though she'd given him her best, she still wasn't good enough for Theseus. "He abandoned me, though I felt moved to save his life. He abandoned me, though I gave him the tools to save his life. He abandoned me, though I sacrificed everything for him. What good am I?" The god Dionysus overheard the mortal woman, and came to her, begging her not to take her own life. "What good am I, who could not keep Theseus?" Ariadne cried, and the god answered: "What good is Theseus? He abandoned you, though it was your compassionate heart that sought to save his life. He abandoned you, though you were clever enough to give him the tools to save his life. He abandoned you, though you sacrificed everything to be with him. What good is Theseus?" Aaaand then they got married and she ascended to godhood and they lived happily ever after in a drunken stupor on Mt. Olympus, as Dionysus is the god of wine and revelry and a bunch of darker things but HEY.
Much more apt to Solas and Lavellan is the myth of Eros and Psyche.

Blah blah blah, Eros's mother Aphrodite is jealous of this mortal woman's exceptional beauty, so she tells her son the god of ~love~ to punish her... only, he falls in love with her instead, and there's a whole bunch of prophecy mumbo jumbo about how Psyche's destined to marry a monster, possessed of power against which men and gods are equally helpless. On their wedding night and every night after, the monster insists that she never see him - it's got to be dark, or she's got to be blindfolded. But one night after what I can only assume was some
really fantastic lovemaking, Psyche's curiosity gets the better of her and she lifts a lantern to her husband's sleeping face for the first time... wooop, it's a beautiful god with wings. He freaks out because she didn't listen to him about the whole "you're not supposed to see me" thing and takes off.
Anywho and otherwhen, to repent she ends up slaving away for his mom, who makes her do a bunch of impossible tasks... while heavily pregnant (ruuuuude). Eros is very likely helping, because ain't no mortal surviving a bunch of flesh-eating sheep otherwise. Psyche proves that she's a grade A badass by being the only fully mortal and the only woman to go to and from the Underworld... WHILE HEAVILY PREGNANT. What a trooper. Anyway, she proves herself worthy of being the bride of the god of love, Eros learns that if you tell someone not to do something they will definitely do it, and awwww they become Heart & Soul, very precious.