Slip Slip Knit

From BluWiki

Insert the right hand needle into the front stitch of the left hand needle as if to knit.

Move the stitch over to the right hand needle.

Insert the right hand needle into the next stitch of the left hand needle as if to knit.

Move that stitch over to the right hand needle.

This twists the stitches. Now transfer them straight back to the the right hand needle.

Insert the needle into both of the stitches as if to purl (the yarn stays in the back of the work). Wrap the yarn as if to knit and pull through as if to knit.

Slip both stitches off the needle and you have a left-leaning decrease.

The video is here.