Yeah girls want BS to slip in at level 4 as interchangeable with BJ or they try to sneak it in as another price point altogether. In most cases it is a total waste of time, ranging from girls who only rub their tits over you to others who lean forward so only their pubes are rubbing against you. But if you find the right girl then it can certainly be a great option because if she gets into it also then it can lead to a completely different experience.