I masturbate with..
But again, i've always been ambidextrious, or multi-dextrious i should say. I can perform some tasks with either hand w/ ease, some with either but preferring one or the other (depending on the task), and some with one or the other exclusively.
Whenever I change hands, the change in sensation is very noticable, without doubt.
It doesn't feel right the other way around!
I'm considering trying to build up my dexterity in my left hand so I can write with both again though.