She thinks Josh's actions were her own

Josh paused as he saw his mother's eyes flicker open. He hadn't considered how she was going to react waking up naked, possibly still leaking cum and in bed with her son and his girlfriend. She sat up and stretched, looking around the room with bleary eyes "morning sweetie" she smiled "that was incredible, you're both such... passionate lovers". Realising it had gotten dark she reached for the alarm clock on the bedside table "oh my, is that the time? I really should be getting on with things" she stood up, causing a trail of jizz to leak out and run down her thigh "although, I should probably shower first" she laughed "we're definitely doing that again though".

Josh watched her ample buttocks sway seductively as she sauntered out of the room. He sat down on the bed, Anna rolling over and falling asleep again as he did so. So if he made decisions in someone else's body they would believe it was their own choice once he swapped back, this opened up a whole heap of opportunities.

He glanced around the room as he planned what he should do with his powers next. There was always both of his sister's room, or he could continue having fun with his mom's body. As he toyed with what to do next his eyes were also drawn to his girlfriend's discarded clothes on his floor, maybe this was a good chance to give her a bit of an attitude adjustment.