No, not at all. Interesting question. It sounds like, though, that he may not be your dependent going forward. That happens, and I'm happy it does :-).
Actually our 32 y.o. son still lives with us, but he works, we charge him some rent (which we don't have to pay tax on since he's family and we don't have a formal contract,) and he takes his own exemption and pays his own taxes. For all of this I'm glad, not sad. Besides those deductions for dependents aren't all that large anyway.
