The same things do get old. Role-playing, schoolgirl spanking, OTK. Try a little ginger root, peeled, in her bottom, before a spanking. Make her hold it in, or get extra spanks!! Peel it so that is it smooth and IMPOSSIBLE to hold in!! A thong might help hold it in, :) The ginger root gives a REALLY HOT sensation, in a sensitive area!!
A past GF also got really excited when I offered her panties with the double-layer crotch part soaked in an olive oil, and red pepper flake mix. Only a LITTLE SPRINKLE of red pepper flakes, in the oil, and just set her panty crotch in the dish for about ten minutes. She LOVED how it 'TINGLED' then 'BURNED' just a bit to make her wet!!
Try a little Vicks Vapor rub, just around the rim of her anus, not inside!!
If you do any of this with her, you have to be willing to let her do it, with you too!! Don't miss out on THAT FUN!! Just some things that I have loved with others... Have fun!!