in a couple of days she won't remember anything anyway...
I was wondering when I read the post if she was like 10...or old enough to have body issues and ask the REAL hard hitting questions.
If you're THAT worried about your two year old walking in on you, make sure you "pass the time" in your own bedroom...its safer that way...
And for the record...telling her at TWO that it was playing is far better than mommy likes it when daddy pulls her hair cause we're in love and mommy and daddy play in each other's pants...
Laugh it off...wait til they're older...and ask where babies come from...OR WORSE...
Good luck to you.