I once believed (смешанная)

When Astarion was very young, his mother told him a beautiful story about soulmates. That every creature was destined to meet someone, whose soul was a perfect match to their own. A simple innocent touch was all that was needed to find out ― a mark of a bright color would appear on both his and his soulmate’s skins for a few moments in the place where they had touched. And from then on, his mother said, there would be no other being in this world that would understand and love him nearly as much as his soulmate.
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Soulmates prompt: A touch of skin to skin from your soulmate will leave an imprint there
OR
They can only find out that they are soulmates through touch, but Tav is being too mindful and refuses to have sex with Astarion despite him offering twice. Astarion is confused. This should be a tag...