Charlie Sheen and Lindsay Lohan only spent one day together filming "Scary Movie 5” in September, but that didn’t stop him from gifting the actress with a $100,000 check – and now he’s explaining why he did it.The "Anger Management” star tells The Daily Beast producers offered him $500,000 to play himself for just a few hours in the spoof film … until they decided to hire Lohan. Then, he was informed his salary would be cut to $250,000 in order to also pay the actress, with whom he shared a comedic bedroom scene. But when Sheen asked Lohan what she was earning and she replied only $100,000, the numbers didn’t add up. "So I just gave her $100,000 of their money,” he says. "Paying it forward.”And the financially-strapped 26-year-old gladly paid the sum forward to Uncle Sam, although it just barely made a dent in the $233,904 she owes in back taxes from over a period of years, beginning in 2009. And how did Lohan show her gratitude to Sheen? She didn’t … until three months later, in December, and only after he publicly complained that she never even said "thank you” for the check he had mailed to her. According to TMZ, she sent a belated bouquet of flowers to his L.A. home.Agencies