Natalia just continued to suck on him although after a little bit she was popping off of his cock, and just looking at him for a brief moment in time, an innocent smile on her lips.
While this happened.... at some point in time Sebastian and Thea had ended up undressing, although perhaps for the same reason, perhaps not. Sebastian had ended up stripping off his clothes because they were uncomfortable, so now he was just sitting in the bed in his boxers.