Wh-what? Why was she asking this? Dan knew he was headed for trouble, this was a trick to see which was the real Danny. But...why in the Ghost Zone would Danny know what Misha's pyjamas were?

Unless he slept with her. It was highly unlikely, and an option that Dan would rather not think about, lest his sanity (or what was left) be destroyed.

But he stayed composed. Let's not reveal myself until she's completely sure.

"M-Misha! Wh-why would I know that?" he stammered in shock. "That's a personal thing, I don't--I mean--I-I--!" Dan continued feigning shock, hoping it'd throw her off guard.