I just uploaded the fourth issue of Magic Boobies to http://www.strongandstacked.com today. I'd been working on this one for a while. Was trying to decide where to go with the plot, and ended up making the general theme being that Jenny is headed toward a darker path if she doesn't stop using her big new boobs and buns to control every man she meets. Sarah on the other hand is trying to walk along a path of goodness, and has to figure out how (and if) she can pull Jenny back from the brink.
While that's kind of the overall background theme, the reality is its fairly light stuff with a lot of showcasing of the girls' giant magical tits and bubble butts.
I'll be working on an update for begiantess.com next