Mandee ~ This sounds a lot like a family horror story regarding a cousin we rarely see, and one of my sisters. The cousin invited herself over "for a visit" (turned into several days). My bil finally told my sister, "I don't care if they are family, you get rid of them, or I will". By this time, cousin had discovered their brakes were bad on their car. When sister asked them to go, cousin brought up the brakes. "We can't drive with no brakes!" To that, sis responds: "Drive real slow". LOL Then, prayed them all the way home. There were some pretty hurt feelings over that one for many years. Even my mother couldn't believe sis sent her cousin away with no brakes in the car!! But...the things the kids did, and her husband!
IF these people invite themselves over again, maybe you can sweetly say something like: "Perhaps when the boys grow up a bit, and learn to behave in civilized company." They need not know you're actually thinking: "sure....when pigs fly".