I second shorts or a belly band or bitch panties. Or, if he will tolerate it, those big inflatable
neck tubes that act the same as a cone, without being a cone. basically just makes it so he cant bend his neck in a U to reach back there, but he can still reach his front feet, water, food, toys, etc. Good luck! and yell at your mom!! that was very irresponsible and for someone whos raised at least 1 kid (do you have sibs?) she should know better!