The guy's imagination is not taken away. Waited for the girls to watch a horror movie and then came over and fucked each one in turn. When you wake up and see a mask, you involuntarily increase your state of fear. And this adds a twist to sex, more hormones are released, including adrenaline. it is possible that such tricks he and his sister and girlfriend will do regularly.
In the hospital, every man looks at the nurses. Especially since they themselves do not try to hide what they have under their gowns. So the desires there only escalate, and a good discharge into their mouths - goes for the benefit of the recovering body.