With undergarments I will just stick to the bathroom/my room, and maybe maybe if no one is home I'll wander to the Laundry Room if I need to take clothes out of the dryer to put on. But never if there is people in the house. Sometimes I'll wear shorts and a sports bra or something around the house when it's really hot, but only when we're not having someone over.
Pajamas is another story. I wore my pajama pants to the Mall of America this part Saturday, because we were later going to be getting on a plane and I want to be comfortable. And speaking of planes I wore my full pajama set to the Airport when we were heading to Minnesota. Though despite those times, I would probably only wear my pajamas to the gas station or something, or if I'm going to a store just to pick up something at night and I had already tossed on my pajamas.
Of course, up until two or so weeks ago my pajamas were usually just a pair of gym shorts or something alone the those, and it'll probably go back to that when it's summer. In that case, I'll go out in public in gym shorts if I don't feel like putting on something else.