The longer they wait to talk about this, the harder it will be, for multiple meanings of the phrase. Better to do it now while there's still some change of Crowley being capable of rational thought, as much as he can be with Aziraphale (Aziraphale! Without a shirt!) leaning over him and beaming down with unquestionable affection (ngk) while talking about cocks and bathing naked (NGK).

"...right." He's saying that a lot. More words needed. The sooner he can words, the sooner they can go back to kissing, and other things. "Right. Cock is probably easiest then, you've had one before and they're not hard to figure out. I'm happy with anything."

He stops again, takes a long halting breath, looks up more seriously. "You know that, yeah? I mean it. Whatever you want to try, or not try, I'm fine with it. Cock or cunt or both or neither, on either of us, anything. If you want me to change what I'm sporting, I will. Just say the word. I haven't got a preference, I just want you. Whatever you'll give me. "