I don't think Xiao Man is a dense person. She has shown good emotional intelligence. I think she's like a fool because she's so distracted by her happiness at spending so much time with Fei Ran.
Aw darn it I like the second male lead more than Fei Ran at the moment. Xiao Man is a bit ditzy though isn't she? I think that is part of why I'm sticking with this though. She is just so fun to watch and so pure you want to root for her
I think that by "I'm only showing you my chips" he was might be referring to a strategic board/card game, meaning that he's very confident; so much so that he's willing to not hide his power at all, just as a show of superiority and dominance.
Haha, like a lot of people actually said before, I think " showing my cards" is more typical though.
(I'm sorry, as a part-time proofreader I tend to give very specific and rather lengthy readings on foreign phrases, idioms or the like... )
All just some suggestions, nonetheless.