Seriously, You're pissed off, and we don't know the whole story. The picture you're painting of Ryan right now makes us all want to say "fuck yeah, kick his silly ass out". If he really is that big of a pain in the ass, let him go to Zygote donor's house. If he is 18, he isn't running away. Just make it very clear that if he leaves he isn't coming back. If you have a really big heart, make him live at mom's for a month on a "trial" basis. Exactly one month later (not sooner or later), he has to decide what he wants, and thats his "final answer".