What if my buyer wants me to stay personally liable on the lease as a condition of the deal?

This does happen, and it's a different kind of pressure than a landlord's — here, your own buyer is asking you to remain on the hook, usually because they see your continued exposure as protection for them, or because the landlord themselves won't approve the assignment without you staying liable in some form, and the buyer is simply passing that condition on to you.

Whether to agree is a business and risk decision, not a legal requirement — you're generally not obligated to accept continued personal liability just because a buyer wants it, and doing so should come with something in return, whether that's a higher price, an indemnity from the buyer for any claims the landlord brings against you, or a time-limited scope rather than open-ended exposure for the rest of the lease term.

Because agreeing to this changes your risk profile long after closing, it needs to be reflected clearly in the purchase agreement — including any indemnity protecting you if the buyer later defaults — rather than left as an informal understanding. A Treadstone business lawyer can help negotiate protections if you agree to stay on the lease.