What should one do if they hear someone invoke blessings upon the Messenger (peace and blessings of Allah be upon him) while they are in the bathroom?

It is disliked to mention Allah verbally in a place where one relieves oneself. This dislike intensifies during the act of relieving oneself. Therefore, upon hearing the mention of the Prophet (peace be upon him) in the lavatory, one should send blessings upon him in their heart, and then it becomes permissible to move the tongue to send blessings upon him after exiting. Mentioning Allah by heart is always permissible. What is disliked is mentioning Allah verbally out of reverence for Him, with the exception of saying "Bismillah" (in the name of Allah) before ablution if it is impossible to perform ablution outside. It is disliked to mention Allah or speak during relieving oneself, unless it is out of necessity. Even if one sneezes, they should not praise Allah verbally, nor should they return a greeting. This dislike is a minor (tanzih) dislike.