Should you wet your toothbrush before or after squeezing out the toothpaste?

It's a debate as old as, well, the existence of toothpaste and toothbrushes : Are you supposed to run your toothbrush under the tap before or after you squeeze on the toothpaste? For reasons unbeknownst to us, the debate was reignited last week on Twitter, as people battled aggressively on either side. There are those who always wet their toothbrush before applying toothpaste, in an attempt to make the toothpaste stick to the brush and soften the bristles pre-brush.