"Light. Do you want to have sex?"
Light almost choked on his sip of coffee. Think. He had to play this strategically.
If I immediately say no, he'll definitely think I'm Kira. It's too obvious. Would Kira have gay sex? Kira would never let himself be in a position so vulnerable, never mind gay or not. Though... Would he? Kira, albeit drawn from me, is a concept who exists in a divorced state. While I may not jump at the opportunity for sex, someone such as Kira may see it as a show of power. So if I declined here, L may suspect that I don't want to come off as too power-hungry, and accuse me of being Kira.
I have to go through with it. I don't have a good enough reason to reject him.
But if I say yes, that still points towards Kira, who could use the argument that "a hole is a hole" and therefore top. No, if I suggest topping, he'll definitely think I'm Kira. But wait. That's it.
I'll take his dick up my ass, proving that I am neither homophobic nor Kira.
L, in the meantime, ate his cake without so much as giving it a second thought. His trap was well-laid and well-prepared.
If Light asks me to top, he's definitely Kira.