With the sleeping girl, keep trying to grab the key until it says that she's going to wake up next time. Then choose wait and keep trying to get the key until it says that the girl's grip is to tight. After that, start fingering her (keep in mind that every time you get the message that the girl is about to wake up, you have to choose wait). After a bit, you'll get the message that her grip has loosened, after this message you just need to take the key from her.
The key in the mechanical arms, just grab it.