42mm band fit a 38mm?

I have not tried it myself, but I have read that the bands will work interchangeably, but might not look quite right. A large band on a small watch will stick out beyond the edges of the watch, and there will be a visible "gap" if a small band is used on a larger watch. It appears that the locking mechanism at the center is the same on both sizes. I've been wondering myself, since I have a 42mm and many of the more "fun" or feminine third-party bands only seem to come in the 38mm size.

No because the part of the band that slides into the top and bottom of the Watch (the connector) will be wider if it is made for a 42mm watch than ones made for a 38mm one. Even if it were to lock properly, it would be sticking out at both ends.