The classic, "I forgot"

"Okay, today we are going to be reading with a partner.  You need to have the same partner as last week.  Find your partner and then come get your book from me."  Simple instructions, right?  Most of the class has no problem remembering who their partner was.  It's only been a week.  Then there are the few students who "forgot" who their partner was.  Really, this just means they don't want to be with that same person.  Do I let them get away with it?  Yeah right.  "You need to remember," I tell them.  After a few seconds of me staring at them, waiting for them to "remember," they realize they are not going to get away with that excuse and they magically "remember" their partner.  Classic.