it's what i do most of the time...infact unless I am having active sex, and I am on top yea thats what I do. I never use lube. I'm lazy.
It's really sad, well sad isn't quite the right word. But it does effect you long term you do really lose sensitivity and you don't notice till it's much to late to do anything about it.
I mean...I have trouble keeping it up, IF I am not actively stimulating myself. Yea I wake up with morning wood but it doesn't stay up for long on it's own lol.
I know this is TMI for most but as a warning, take my advice. Use lube. I wish I did when I was younger I'd be much happier and probably able to do more cool things like hands free orgasms.