The title is not really my question, but let me first speak about the spoiler level.
This question points to an event that occur in A Storm of Swords (mid-book ?). Its equivalence in the TV show is Season 3, episode 6 and later. Stop reading if you didn't read/watch this part of the story and don't want to be spoiled. Do not read anything below the spoiler tag even if it's not in a spoiler tag because it would make you understand what is in the spoiler tag.
This is about Tyrion Lannister and his relation with Sansa Stark.
They get married.
But how is this possible ? Tyrion was previously married to Tysha, a whore that (end of ASOS spoiler alert)
actually wasn't a whore
and all we know about her (Tywin Lannister's words) is that
she was sent back to "where whores are sent"
But was the marriage cancelled ? How is that possible ? Tysha surely wasn't a virgin, and nothing is said about her being dead.
So, my question: Did they just divorce? Is that possible? Or maybe Sansa'a marriage with Tyrion is not valid?