Question For The Ladies

My wife gets me so confused sometimes I just don't know how to deal.

My wife the other night was talking about one of our first times having sex in a hotel room when we first met. Doggystyle in front of a mirror I pulled out and shot my load all over her ass, back and hair. She said she misses wearing my cum. Sometimes she spontaneously gets in the shower with me sucks me and tells me to cum on her face. Now when this happens she gets so upset because when she gets out of the shower she always has cum residue on her and gets pisses off complaining that is impossible to get all the cum off.

When she wants it on her tits she first rubs them with an oily soap which i don't think helps.

So whats the best way to wash off cum most effectively?