There exists no assumption of permissive use in the State of Mississippi, the burden is on the driver to prove they were given permission to drive the car in question. This matters because if the driver of the car was given permission, it is possible the owner could be sued under the Permissive Use law. Basically, this means you gave the driver permission, so you are liable for the damages. This can be referenced in State Farm v. Bridget EAKINS, Doris Winters and Duane Quarles, a case in Mississippi where the defense tried and failed to prove permissive use. This case shows us both real world example and in Mississippi, there is no assumption and permissive use must be proven.
As to being personally sued, most insurance policies will include a permissive use clause. This covers the owner should a scenario like this play out, and in particular if the driver of the car has no insurance of his or her own. It is important to inquire about permissive use with your insurance when selecting a policy, just as it is important to understand the implications of allowing someone to drive your vehicle.