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

1.
used to give someone permission to do something or to accept an offer
:
•
“Can I borrow your pen?” “Be my guest.”
•
If you want to use the computer, be my guest.
used to give someone permission to do something or to accept an offer