Slipping purlwise

I am working on a pair of toddler blue jeans. The pattern states to slip the first stitch of each row purlwise. When the pants are sewn together the selveges will be visible. Here is my question: when I slip the first stitch of a knitted row purlwise, do I keep the yarn in back of the needles as if to knit when I slip it or do I bring the yarn in front of the needles, slip the stitch and then bring the yarn to the back to knit the rest of the row?

I think you can do it either way. I slip with the yarn forward and then move it back.