seller requests to stay in the property post closing

[Alex Loginov]

Hi, we are buying a house, but the seller requests to stay there post closing in exchange for some seller credit.
They say it's a requirement for them and they can't go forward without 2-3 weeks of post occupancy, before they can move out to their new home.

What can we do to protect ourselves from them staying longer or not wanting to move out? We already asked them if they can provide us with a proof of arrangements for their new home, like a purchase contract with the closing date.

Would appreciate any advice on this tricky situation. Thanks!