Well, I don't think this mature madam is the grandson of this overgrown man. And from the way he talks, he apologizes to her first, not as his grandmother. The age of this lady is certainly not young, but her pussy and tits are quite well preserved and still quite firm in appearance.
That's what a personal assistant is for, to always be there when the boss wants her to be. And to do what he demands. This man wanted to relieve the tension - the assistant was at hand, without hesitation and took advantage of her. According to her cries and sighs conclude - this is the work she likes!
What is the name of the pose at the end?