When Tyrion Lannister was very young, he met a wheelwright's daughter on the road, apparently the victim of an attempted rape. Whilst his brother Jaime ran off the attackers, Tyrion helped Tysha recover from the ordeal, and they became lovers. They found a wandering septon willing to marry them and briefly, they lived as husband and wife, until Lord Tywin learned what had happened. Jaime confessed that he organized the incident to make his brother happy, and Tysha was actually a prostitute. In a fury, Tywin had his guards rape Tysha whilst he made Tyrion watch. She was then sent on her way.
Since this incident, Tyrion has disdained love and romance in favor of liaisons with prostitutes for money.
In the books
In the Song of Ice and Fire novels, Tyrion recounts the story in a very similar manner to the series. However, in the series he omits the detail that he was forced to join in the rape on pain of his father's wrath to complete his own humiliation.
- Tysha at A Wiki of Ice and Fire (spoilers from the books).