Congratulations Depraved Shit Bandit!

You'll come in through the skylight on a rope, dangling above your target like a spider on a strand of its own silk.  What will strike you, more than the elaborate security measures, more than the guards, all of them with their backs turned as you descend, will be the odor, or rather the lack thereof.  The shit, trapped within a glass box, will be absolutely odorless.  It will bring with it a strange sort of dissonance, a notion that something is missing, that something requires pursuit.  You'll find the sensation, or rather the lack of sensation coupled with the expectation of sensation, to be decidedly arousing.

Even after you open the glass box containing the shit and remove it from said glass box in a specialized carrying case the odor will still be muted, barely detectable as shit.  It will require all of your will power, all of your self control not to break down and start touching yourself on the roof of the museum, but you'll keep your act together for the trip home, for the elevator ride up to your penthouse apartment, right up until you enter your home.  The moment the door closes behind you, your penis will flip from six to midnight.  Your pants, once ideal for heisting, will suddenly feel restrictive, so much so that you'll tear your zipper in your rush to get them off.

You'll barely even be aware of what your own body is doing as your penis, shivering, grinds against the ancient turd you'll have stolen from that museum.  Hardened by time, odorless, as ancient as the mad Egyptian king who ordered it preserved upon his death, it will, in a single moment be incredibly old and incredibly disgusting, fulfilling both of your requisite fetishes.

You won't last more than a few minutes before you come, explosively and dramatically, semen spraying across the room, landing on your coffee table, staining your walls.  You'll feel at once drained and satiated, so much so that you'll pass out on the floor.

When you come to your head will be pounding.  The faint odor of the ancient shit will no longer seem enticing; after your conquest, it will strike you as stale.  Dead, at best.  Staring at it, you'll suddenly hate it, hate yourself for wanting it, for breaking into the Smithsonian to steal it, to fuck it, to ruin it, not just for yourself but for all mankind.  Amidst this storm of self-hate, an ultimatum to never steal ancient shit and take it home to fuck it will take hold within your mind.

This will be a normal part of the shame cycle that drives you.  Ride it out.  Drink some chamomille tea and go to bed.  Try to wake up early and go for a jog the next day to clear your head.  You'll soon learn of an ancient Aztec shit on display in a museum in Seattle, and you're going to have to start planning right away if you want to pull that job off.

Congratulations Depraved Shit Bandit!