At the listing appointment it is important to determine the marital history of the Sellers. Ask if they were married to each other when the home was purchased. Even if the answer is "no", you should be aware that both spouses may still need to execute closing documents. For example, if both spouses occupy the property, it is likely that it constitutes their legal homestead, so the spouse not shown vested in title (the non-purchasing spouse) will still need to convey his or her homestead interest at the least. If the property was never homestead (i.e. an investment property) and remains the separate property of the purchasing spouse, then the non-purchasing spouse may be able to sign an Affidavit stating the property is not his/her homestead and he or she would not join in signing other closing documents.
If you are working with Sellers who are in a pending divorce situation, unless the divorce is final (judge has signed off on the final decree and the decree has been recorded in real property records - or the judge has signed the decree and a Deed has been obtained from the ex-spouse and filed of record conveying the property to your Seller) then the property may still belong to both spouses. In this case, both will be required to sign at closing and the proceeds check from closing will be made out to both of them (unless otherwise stated in writing from both spouses).