If you like slowly displacing your SI joint day-by-day, feel free to place your valuables in your back pocket and sit on them.
I personally put my phones, keys, and wallet in the front in preparation for a mugging. I think it's a lot more sensual to be caressed at the thigh. I'm not against having my ass grabbed, but when it comes down to it, I prefer to not degrade my spinal alignment every time I sit down.