Experienced man, to whom young girlfriends asked for sex, rightly distributed their forces. While he fucks one, the other excites her clit with a toy. Everyone is in business and satisfied. If you change partners, then long over her not have to pant - can quickly cum or jump on top herself. And the girls do not get bored, all the time caressing not only themselves, but also their partner.
That's what I understand - a course of treatment! The nurses 100% graduated with honors from medical school!