snug fit or loose fit?

[burger'n'fries]

Does wearing my watch loosely, allowing it to slide freely above and below the Ulnar styloid (wrist bump), cause unnecessary wear or strain on the movement?

It does seem to jostle around more so than if it was snuggly fitted to my wrist, and I tend to shake my wrist when the watch gets stuck. Am I damaging the movement when I do this?

Here's a photo to help articulate what I mean by my watch sliding freely. The watch is able to move freely to either position displayed.

Also, take it as a size comparison. The TAG has a 39mm case and the Explorer...well, you know.

What do you guys prefer, a snug fit or loose fit?