Mariah & Nick Go to White Castle

1/7/2009 4:10 PM PST BY TMZ STAFF
Doesn't look like the underwhelming-yet-overpriced sushi at Japonais did the trick for Mariah Carey and Nick Cannon, 'cause right after, they parked right outside Slyder heaven -- White Castle.

Sadly, this was one trip without a cameo by Neil Patrick Harris.