be my guest
US /biː maɪ ɡɛst/
UK /biː maɪ ɡɛst/

1.
请便, 请随意
used to give someone permission to do something or to accept an offer
:
•
“Can I borrow your pen?” “Be my guest.”
“我能借你的笔吗?” “请便。”
•
If you want to use the computer, be my guest.
如果你想用电脑,请便。