I was gonna suggest the noise was his nuts, rattling around in Steph's purse, but he hasn't been married that
Agree w/ Bob, the wheel not being centered correctly in the dropouts is the first culprit to check.
Next, make sure the cassette lockring is tightened snugly.
Also - you could have a broken spoke, a loose or missing chainring bolt, loose seatpost clamp or head, maybe yer crank bolts aren't tight enuff.
There are lotsa things that can cause annoying noises, and they don't always sound like they are where they are - the tubes on a bike can make something like a loose saddle sound like a BB problem - believe me, I've been there.
(I had that exact above problem - coulda sworn it was something to do w/ the BB or cranks, when it turned out that all I had to do was lube the seatpost/seattube, and where the seat rails met the post head, and then it was blessed SILENCE.
Oh, thought of another annoying potential noisemaker - loose bottle cage.
Or even if ya don't have one, maybe the hex nuts for where one could go are loose.