That is your problem, you always complicate issues, what has Prophet muhammad has to do with this issue, How many times pastors and reverend fathers were caught in sex scandal have you ever heard that the issue linked to JESUS piece be upon him , so be careful.   

Those people that engaged in this act are not human being, they are pig, they should remember one day they will die and surely they will be punish for their abomination.     

I don't think this will become a point of discussion, washing your wife wears is something that will strengthen the love and affection between you and your wife, so to me is good not always most especially under wears when she is sick.