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!
Come on, she was in pain! It's just that she hasn't had her asshole properly fucked yet! Once you get a group of students up your ass, you'll get a taste for anal. And then you can move on to the teachers. You'll be earning good grades.