Got to Go Check Something

Aubrey: (walks by Ingrid)
Ingrid: Aubrey, did you just fart?
Aubrey: (smirking, sheepishly) Yessss.

...a few minutes later

Aubrey: (walks by Ingrid)
Ingrid: Aubrey, did you fart again??
Aubrey: (sheepishly, smirking) Yesss.
Me: Aubrey, did you fart or did you forget to wipe your butt?
Aubrey: (pause) Ummm....I just got to go check something

From the bathroom...
Aubrey: uh, MOM. We're gonna need some new underwear in here.

....
within 30 minutes

Aubrey: (exits bathroom)
Me: Aubrey, did you wipe your butt??
Aubrey: (annoyed) Yes Mom!
Me: Did you wash your hands?
Aubrey: (pause) I just have to go do something.