well, pinkfinite is real. 

maybe he's smirking to hayoung or (i hope!) its to naeun. 

meaning of lips :

-nervousness 

or

- a clear sign of attraction. (you know what i meant?:p)

sunggyu avoiding eye contact :

meaning:

Movements that avoid or minimize eye contact

• The eye shuttle. When people flick their eyes back and forth, they are probably looking for an escape route.
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• The sideways glance can mean a few things. If you look at someone out of the corner of your eye and smile, you show interest. Looking out of the corner of your eye with a raised eyebrow shows interest too. If someone looks out of the corner of an eye when you are talking to him or her, it would be best to change the subject because the listener isn’t interested in what you are saying. 
  People look towards things they are interested in and away from things that don’t. You will show lack of interest by not looking at someone when they are speaking to you. (This is i guess what myungsoo did :p)
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• The eye dip. Averting your eyes downward is an attempt to hide your feelings. It also can mean that to give control to the person who is speaking.

credits : to the right owner pic isnt mine!