Fighter
Pro Adventurer
Yuffie seemed clueless, actually. I think there's even in a line in the UO or some book that said Yuffie was surprised Cloud was being so kind, not realizing he had just spent the night with Tifa. (Yes, I'm pretty sure it actually said that. Doesn't that make things pretty clear?)
CloudUO said:p. 39, Yuffie's file page: the marked part)
*According to Cloud’s suggestion, Yuffie gets off the airship in order to make sure the reason to fight for.
"Gee, Cloud...... that's so nice of you to say that. ......You
sick?"
---It’s the line to Cloud, who welcomes her kindly when she returns to the airship.
Exposition:
Yuffie doesn’t know that Cloud just spent the night with Tifa alone. Woman’s intuition is sharp, indeed?