I think he suspects in canon but doesn't have enough info to say yes or no. Thomas' reaction to him here was the extra information he needed.
That's probably why he hasn't said anything to Harry. "I know that your boyfriend/ex is actually your brother. Wanna go out some time?" isn't going to get you a second chance if you're wrong.
Re: Warlock Games 4/10
(Anonymous) 2011-03-19 09:00 pm (UTC)(link)Also,
SQUEEEEEEEEEEEEEEEEEEEEEEEEEEE
Re: Warlock Games 4/10
That's probably why he hasn't said anything to Harry. "I know that your boyfriend/ex is actually your brother. Wanna go out some time?" isn't going to get you a second chance if you're wrong.