It feels like you should be using lube.
Best case scenario is the inserted object inserts as if lube is present. Worst case scenario is both the inserting and receiving objects are so dry that penetration is unsuccessful, not to mention painful -- what's the point.
S&M, however, is an entirely different discussion. Even so, if you want to feel or inflict anal pain, there are a lot more efficient ways than the presence or absence of lube.
Best case scenario is the inserted object inserts as if lube is present. Worst case scenario is both the inserting and receiving objects are so dry that penetration is unsuccessful, not to mention painful -- what's the point.
S&M, however, is an entirely different discussion. Even so, if you want to feel or inflict anal pain, there are a lot more efficient ways than the presence or absence of lube.
