Some advice?

Today while I was at my fairly new job, my purse in the break room was moved because it was sitting on a tray that was needed. When my purse was moved, a little bag of coke fell out. My coworker sat it back on my purse. I waited until everyone left the break room and quickly grabbed it, hid it and moved my purse elsewhere. If my coworker tells my manager, is this grounds for termination?