when she says “I cannot understand how you could expect a beautiful apartment to remain unoccupied indefinitely” she means that he shouldn’t expect her to remain a virgin.

when she says “As for the heat, there is plenty of it, if you know how to turn it on” she’s saying that he doesn’t know how to turn her on.

when she says “regarding the space, the apartment is indeed of regular size, but if you don’t have enough furniture to fill it, please do not blame the management.” she’s saying the furniture is referred to as his penis, and that it’s small.

when she says “Please send the rent in full or we will be forced to contact your present landlady.” she’s saying that the ‘landlady’ is his wife, and she will tell his wife if he doesn’t pay the full amount.

It’s very funny guys, you just have to think a little dirty.