Ryan decided the best approach would be to turn on the charm and casually slide into the topic with her. He curled his little 5'8" frame into a chair near her and while nonchalantly playing with his toes softly told her, "You're like a big mystery and I'd love to learn more about you." When she indicated that she was okay with talking about it, Ryan then proceeded gently to ask her all the questions he had about her decision and surgery.
They covered what led up to Katelynn's decision to rectify her physical gender and then all the details of the surgery itself. Not knowing what the proper responses should be in that type of conversation, Ryan just let his boyish charm shine through as he expressed his interest and genially showed just a little of the shocked reaction he felt from hearing about sex organs being detached and remodeled.
He couldn't totally hide his horror at hearing about a person deliberately separating themselves from their penis. For all males that identify as male it is the stuff that traumatic nightmares are made of. It's not just a boy's best friend, it's the core of who they are and not something that a person in their right mind would choose to lose. Given that circumstance, Ryan did a pretty good job of being a sensitive listener.
It should be noted that this scene during the taping of the show seems to have captured Ryan at his most adorableness. His hair and demeanor were particularly cute. It was a vision of Ryan's "good" twin that was the total opposite of the side that was yelling at JD in the previous episode over the shaving cream.