Some people believe that having sex should require equal effort from both partners. After all, sex is a means of sating a person's desire for sex, right? Thus, it is only fitting that you return at least as much as you were given. Did she give you an incredible blowjob? You ought to thoroughly lick her behind as well! Furthermore, you should be expected to fulfill your end of the bargain and enjoy her until she experiences an orgasm as well if you initiated the contact, which is typical for most males. Unless one of you or your spouse enjoys dominating sex, this should be the standard for any couple.