what's the difference between peanut butter and jam?

jam [美] [dʒæm] [英] [dʒæm]
动词（及物） ( jammed; jammed; jamming)
塞进;挤进;把...塞满;使挤满
Thousands of people jammed the stadium. 成千上万的人把体育场挤得满满的。
The bus was so full that I was jammed in and couldn't move. 公共汽车是如此拥挤,我被挤得动弹不得。
He jammed four apples in his pocket. 他把四个苹果塞进口袋。

花生酱不能X屁股

这是一个笑话，看完就明白了，有点恶心哈
Peanut butter & jam

A guy says to his wife, "I'm in the mood for some 69."

She says, "It's that time of the month, but if you don't care, I don't care."

They go into the bedroom, and are 69'ing like mad dogs when the doorbell rings.

She says, "Answer the door."

He says, "But my face is a mess."

She says, "It's just the postman. Answer the door, and if he says anything, just tell him you were eating a jam sandwich."

He opens the door and says, "I'm sorry about my