"We never shower in the afternoon."
Translation:Nunca nos duchamos en la tarde.
Because this isn't the verb duchar (to shower), but the reflexive verb ducharse (to shower oneself). The 'nos' is actually treated as if it's part of the same word as the 'duchar'. So nunca (or any other word) isn't allowed to separate the two. So it has to be nunca nos duchamos.