If one of them committed a sin the Prophet of Allah, sallallaahu 'alayhi wa sallam, would stop him:

'Abdullaah ibn 'Abbaas narrated that Fadhl (a Companion and the Prophet’s cousin) was riding behind the Prophet of Allah, sallallaahu 'alayhi wa sallam, and a woman from the tribe of Khath'am came, so Fadhl began to look at her, and she looked at him. The Prophet of Allah, sallallaahu ‘alayhi wa sallam, turned Fadhl's face away from her. The woman said: "O Messenger of Allah, the obligation of pilgrimage has reached my father while he is at a very old age, and he cannot ride on an animal. Should I perform pilgrimage on his behalf?" The Prophet of Allah, sallallaahu 'alayhi wa sallam, said: "Yes." This was during the farewell pilgrimage of the Prophet of Allah, sallallaahu 'alayhi wa sallam.