You don't need another girl if you have mom that blows best

A young student is looking for apartment to rent. He needs a place to study and a room to bring girls to.
Today he found an ad about beautiful cheap apartment. He met the owner - mature sexy lady and talked about details. Funny, but he can't bring any girls over becouse apartment has certain policy. To his surprise, he woun't need any girls because he's gonna have mom to satisfy his needs. She is a houselord and a girl to fuck around here.
Why do you need another girl if you have mom that blows best?