most occasions, i opt for right hand and it is generally dry. i take my time and love to edge, tasting my pre as it flows from my slit.
left hand is when, somewhat like another poster, i use a lube: saliva or wet or astroglide. i move faster over my slick meaty cock. in an abs, it makes it seem naughtier to be slick with saliva and pumping and added excitement of a public self-pumping makes up for the lack of edging. at home, while my left is wet from lube and pre, i use my right hand to turn the pages of a magazine or to use the DVD remote.
i also love the no-hand feeling with a toy like Fleshlight or a pocket pal of some kind. i lube up my cock and the toy, lie on my back and slide the toy down my cock. particularly if it is a heavy toy, it's like if someone is riding me and i hump the toy as it lays on my lower belly, using my legs to lift myself off the bed fucking and humping the toy. love to hear the obscene slickly wet sound of my meat sliding in and out of a sexy orifice. so, when i cum in this fashion, no-hands, i really spew a load with it flowing thickly out of the toy and down my shaft and into my hairy pubes.
