So, here's something for you guys to try; the next time you are stressed, or just are bored, or want the alternative of a (erm... you know what I mean...) here is something I found helps me. I very lightly scratch my arm. Basically, very lightly press your fingers on the underside of your forearm. (Like you're trying to reach out for something.) Then, just move it back and forth. It's soothing, and isn't sexual.
Just something to try!