masturbatory infidelity
Cheating on your right hand by whacking off with your left hand. Whether it be due to feeling like you're getting some strange or because you are seduced by your left hand wearing a sexy glove or mitten,it's still cheating.
I fell victim to masturbatory infidelity in a moment of weakness. I saw that sexy Dora the Explorer band-aid on my left thumb and couldn't help myself.