P2 *yo, sl1, k1, psso, k2tog, yo, p2, repeat from *
After the P2 your yarn will be in front. You are correct to wrap the yarn OVER your R needle from front to back so the yarn is now in back and a NEW loop has been created on your R needle. Now slip the next st from the L to R needle being careful not to let the YO loop slip off of the R needle. K1. PSSO (which is a decrease to match the YO increase). K2tog. YO, which will start and end with the yarn in back (also this is an increase to match the K2tog decrease). P2.
You should end with the same number of stitches you started with.