Ashield Gurlhosur I think that's why Charlie hired her, he knows he won't have sex with her no matter how intoxicated he will get, as well as she won't run away or feel offended when exposed to the constant debauchery in the house.
+Xylarxcode That would also explain in that dream, Alan has working in a movie theatre. He's an old, balding man while Charlie still looks the same with just a few gray hairs. Charlie says to his date, "Can you believe I'm older than him?"
+Alexander Edward Pytko Stress will do that to you. Charlie leads a leisurely life of pleasure, wealth and joy. Alan on the other hand has alimony, work and a kid to worry about. He's much more easily stressed out. It's common for a man approaching his middle aged years to lose his ability to keep it erect if he's suffering from stress.