I like how the guy fucking his ass makes me think the the dick at the end is actually his dick and fools me into thinking this isn't a trap. Which I fell for.
Of course, this wouldn't work if you already know the character's a trap. Or if this wasn't on danbooru. Which it wasn't. Anyone casually looking at this tumblr might think this is a girl. The only thing I could see wrong with this is the upside down balls.