"my arse" in Chinese (Simplified)
我才不信呢！（粗俗）才怪（粗俗）
Definition
这是英国英语中非常不正式而粗俗的说法，当你完全不相信或否定别人说的话时使用，类似于“才怪！”。
Usage Notes (Chinese (Simplified))
极为口语和粗俗，用于亲密或同龄人之间，不适用于正式场合。常表达对某事极度不信或嘲讽。
Examples
You finished your homework in ten minutes? My arse!
你十分钟做完作业？**我才不信呢！**
He says he can lift 200 kilos—my arse!
他说他能举起200公斤——**才怪！**
You met a movie star at the store? My arse!
你在商店遇到电影明星？**才怪！**
Oh sure, you're an expert now—my arse.
哦，你现在是专家了——**我才不信呢！**
He claims he was at the meeting—my arse! I didn't see him there.
他说他在会议上——**我才不信呢！**我根本没看到他。
You expect me to believe that story? My arse!
你觉得我会信这种话？**才怪！**