F.R.I.E.N.D.S - Emma Laughs for the first time

1 - Who is Emma?


2 - Who is the first person who makes her laugh?


3 - What is she laughing at?


4 - What song do they sing? If you don't know it, google it!


5 - Why do they get embarassed in the end, when all of their friends get in the apartment?