Is he gay??

So I'm a trans boy, and I recently came out to my boyfriend. luckily, he was totally supportive and didn't freak out. he respects my pronouns but lately he's been getting a bit moody. I asked him what was up and he said he was questioning his sexuality. he always thought he was straight but now he's dating me. is he gay? he says he isn't attracted to biological males, but is attracted to trans boys and nonbinary people. he's kinda freaking out, what do I tell him?