It is morally incorrect for one to defile himself, or his future bride(note: iCor.7).
I do not see how one can be showering without carrying it beyond that point anyway.
Nor can you shower before a naked woman without lusting after her body in the process; lust being wrong as well.
Note that I am not claiming perfection in these areas, I am acknowledging my fault-hood, while reminding us of the height of God's expectations of "perfection" (Matt. 5:48)