Most women, especially motivated horny women have a lot more capacity for sex than they realize. This includes how many cocks they can handle, the size of the cocks, and the duration of the encounter. The primary limiting factors for the woman are physical endurance and lubrication. A woman in excellent physical shape, a marathon runner for instance, can be nearly insatiable. However extended sexual activity can result in dehydration, and if the woman becomes dehydrated the first thing that seems to be lost is her natural lubrication. So take a break between bed partners and rehydrate. A good quality lubricant should always be on hand also. I like to have a some Gatorade handy for marathon encounters. You should also remember alcohol accelerates dehydration.