It depends on what you try to pair with. It should be able to pair with BT headset w/o problem although I have one that won't show up for pair but it pairs with my home BT gateway and car system just fine.
If you try to pair with another device as its AW host, you will need to reset the watch first.
If you try to pair with another device to act as BT speaker/headset of that device, the watch won't have that option until you disable the numbersync/sharing feature of the watch.