Adding walls with drywall and painting whole room?

[Matthew Maggy]

This is not a flip or anything. It's a duplex we're house hacking and the kitchen has a water heater out on the open. I built a wall with a door around it and have just finished putting up the drywall and am ready to mud.

The problem is, that the new wall, joins an 2 old walls and the ceiling, which are already painted and what not. I don't really want to have to paint the old walls and ceiling because of drywall tape & mud. Is there a way to seal, or mud the new drywall so that I don't have to tape and feather on the old walls and ceiling and then paint them?

I hate painting.