Two options

Having decided to stay in Mary's body for now Gary spent some time admiring himself in the mirror thinking about all the things he'd like to do.

He's sorely tempted to stay right here and do some intimate exploration. The problem with that is this private room isn't exactly private, he could be interrupted at any time. Perhaps it would be best to find somewhere a little more secure for that?

He's also not fully convinced any of this is real. He thinks it might be a good idea to just spend some time walking around and see how others react to him. He's sure that if he is imagining this whole alien possession powers thing, it'll break down pretty quickly once he's dealing with real people.

After considering it and spending some time playing with his sensitive breasts he decides to...