系in the bed...定系on the bed?

On the bed = 在床上
in the bed 可以是指: 已在被窟內 或 是性行為
但 breakfast in bed 就是指 床上食早餐 (供應早餐倒床上)

可在 www.m-w.com 或 www.dictionary.com 找出正確的意思:
. in bed, a. beneath the covers of a bed.
b. engaged in sexual intercourse

on the bed..因為冇理由訓係張床裏面ga ma~=]

on the bed~~

On the bed