>>51534391A lot of dominance, bit of bondage, bit of imagined tactile sensation. There is a heavy suspension of disbelief (personally, I prefer to ignore the teeth, suffocation, pain from acid burns, and the damage to the pred that struggling would realistically cause), which some people have trouble understanding for some reason.
In general, it's sort of, like: imagine how it feels getting a blowjob or titfuck, or having vaginal or anal sex, and then think "damn what if my entire body felt like this?"