I have come to the conclusion that carrying a knife in your rear pocket is a very bad idea.
1. it's more likely to scrape on random things, like cars and leather furniture.
2. It's easy for other people to reach.
3. My knives would constantly hook themselves on car seats and get lost on the floor, finally my Spyderco Lava disappeared permanently that way and I haven't had a knife clipped to a rear pocket since. YMMV
RNST, you lucky dog.