rollercoasters are the illusion of danger and pain.
actually hurting someone willingly during sex, for the purpose of making the sex better? That is not something that just happens. In my 42 years I have yet to find someone who engages in "risky" sex (bruising, degradation, painful insertions, extreme bondage, sadism, random sex with strangers) that does not do so to either mask, justify, hide, repress, or compartmentalize prior trauma. When this is the only way for someone to get sexual satisfaction? EVEN MORE SO.
what consensual adults do in the sex act, as long as it is mutually agreed, is none of my business, but that does not mean that the impetus behind such sex acts is drawn purely from sexual fun.
Ask around.