Tension is a wonderful thing. I liked it, kept me reading. 2 off-the-cuff suggestions:
1) Don’t say off twice in the same sentence in the first paragraph. 2) Point-of-view is important… So when you say “belly or butt” you kind of break POV. It should say “Arnold patted something, but probably wasn’t sure whether it was a belly or butt.”
neil kant 
thebetweenspace 
Sanglorian