Separate default remotes for pulling and pushing

Hello,

I couldn't find a way to do this, but it seems it would be a fairly common use-case:

I want to set up different default remotes for pushing and pulling so that I can pull from remote a using "git pull" and push to remote b using "git push". This is particularly useful when committing to projects on github, since you may only push to your fork, but you only want to pull updates from the original.

Right now, I can either set the original as my default remote, in which case I must use "git push myfork", or I can set my fork as the default remote, in which case I must use "git pull original".

Please let me know if I'm overlooking a feature already present in git that allows me to have separate remotes for pull and push. Otherwise, I hope it gets implemented in the next version of git!

Thanks for reading,
David