Huzoor salallahu alayhi wa sallam had many wives - is anyone going to dare say he is not ascetic? He would be with his wives but as soon as the azan was sounded Hazrat Aisha (ra) says, "Marra ka alam ya'rifuna", - he went as if he did not know us. This was the perfect level of zuhd, asceticism, that he had. The issue here is the heart. As long as the heart is not bound to the worldly things you're good. This is why shaikh e kaamil is necessary.