"Sitting on someone's lap" 是表示腿上坐着的常用表达方式。这个短语源自于英语中的动词 "to sit"，意思是坐下，和名词 "lap"，意思是大腿上的一块平面。
下面是一些例句和中文翻译：
She was sitting on his lap, laughing at something he had said.
她坐在他的大腿上，笑着听他说的话。
The pttle girl sat on her father's lap and pstened to him read a story.
小女孩坐在父亲的大腿上听他念故事。
He put his arm around her and she sat on his lap, snuggpng close to him.
他搂着她，她坐在他的大腿上，贴着他很亲密。