The anus and rectum do not self-lubricate as the vagina does, and without the liberal use of lubricant the delicate rectal tissue is at risk of.
for sex. In case you are using a condom, once you put it on, In all cases, you can be liberal with lube, as there is often no such.
Before, during, or after — Use lube anytime during sex! But some lubes are better than others, depending on your style. Learn which type is.