What's that smell?

I've been noticing a strong sweaty smell lately in the office. Couldn't figure out where it was coming from. Finally twigged to it today - I bought a new watch with a leather wristband, and I haven't been taking it off for every ride. My last wristband was plastic, hence no smell.

Now I have to wash and disinfect my wristband. The perils of leather and cycling!