She might say, for example, that was so mean what you did. When I counter-complain that I have no idea what she's talking about, she assures me that I was very mean to her in her dream. When I counter-assure her that she's being unfair, or at least slightly insane, she refuses my logic. Sometimes she asks for an apology.
Every once in a while my dream-life doppelganger does something truly reprehensible, and she holds it against me all morning.
1) Never allow wife to fall asleep
2) Convince wife that, as Freud suggested, all dreams are wish-fulfillments and she unconsciously desires whatever bad treatment she receives
3) Enter wife's dreams through Avatar-like technology, so I can battle my malicious double or at least avenge his wrongdoings (hard)