Spanking

I'm not "into" pain, but we've tried erotic spanking.  I think spanking only works if one of you is into being spanked and the other is into spanking.  I let my husband spank me for a solid 5 minutes.  My ass was pretty red.  We both pretended to enjoy it, but when the 5 minutes was over we both agreed to never do it again.

But trying new things is about keeping sex exciting.  You will find several duds.  Keep trying.