TMZ said the bidding at the charity auction started at $20,000 and went back and forth between Pitt and a non-celebrity bidder, who has not been identified in media reports.
Pitt bowed out of the competition when the other bidder offered $160,000 for the experience.
"During the first auction, Brad was on his phone. When the auction announced Emilia Clarke, they called her out in the crowd and Brad literally turned his whole neck to find and look at her and enthusiastically clap," a witness told Us Weekly.
"He offered $80,000 in the auction to watch Game of Thrones with Emilia," the source continued. "Emilia was covering her mouth and giggling. Leo [DiCaprio] enthusiastically watched the whole auction, turning his head back and forth between Brad and Emilia. [Pitt] later offered $120,000 and raised his arms in excitement, but was out at $150,000. He laughed hysterically when he gave up and they called him out for it. ... He clapped and cheered when someone else took it for $160,000."
Sean Penn's gala dinner and auction to benefit the J/P Haitian Relief Organization took place at Milk Studios in Los Angeles Saturday.