先週はパチンコで勝った友人に焼き肉をごちそうになりました。食べ放題でたらふく食べました。
Last week I was treated to dinner by my friend who'd won at pachinko. It was all-you-can-eat so I ate to my heart's content.

一杯ごちそうしようか。
Can I buy you a drink?