안녕, Haley씨!

I'm a Gleek myself! Glee 보는 것 진짜 좋아요! 그런데 Twirly 듣는 것 기억하지 않아요.

twirly - Probably when they dance and twirl around, like a pirouette

"Brittany S. Pearce is doing a twirly dance"

shrooming - Tripping on recreational drugs

"Puckerman is shrooming in the choir room again"

Don't over think it - Don't think too hard or too much over something

and one more question
when will you come back to US for good lol
that 'good' means really 'good'?

The "good" means permanently. So the question is When will you come back to the US to stay and no longer leave.

ahhhh many questions!

Hope I was able to help. 감사합니다!

What does it mean? from GLEE

I'm GLEEKS. :)

apparently it's a tv show in America, "GLEE" so I suppose a person who likes the show is a, "Gleek" playing on the word, "geek" which is a person with an unpopular obsession with something or who isn't welcome in the popular groups in school (until 8 years later when they made ipods and all the popular people needed to buy them to feel good about themselves).

this is some word from Glee.
I'm not sure about that meaning.

twirly - take 2 lengths of rope, hold them both by one end, in one hand, let them hang - twist them around each other, they have then twirled.

(mu)shrooming = mushroom - eating hallucinogenic mushrooms to go on "a trip" - it's like tripping - taking drugs.

Don't over think it - don't think too much, for so much time, about something - 

and one more question
when will you come back to US for good lol - for good means - permanently - it's probably been shortened from something like, "why not come back for the good reasons, which will benefit you" - come back for good..... 

but no it means, "for ever".

:)