DryerLint
Throatfucking your grandmother
Think about it. Not only does she have no emotional reaction, but she rarely feels anything in the first place. This means that you could do all kinds of down and dirty, nasty things to her (or have her do them to you), and it wouldn't matter to her. She doesn't become embarrassed, ashamed or angry.
You could put a dog collar and leash around her neck, get her to tongue your arse, slap her around a bit, call her every kind of name, spit on her, throat fuck her and cum on her face.
You could put a dog collar and leash around her neck, get her to tongue your arse, slap her around a bit, call her every kind of name, spit on her, throat fuck her and cum on her face.