'welcome to hell' has been used in other serials too.
But it is Arnav Singh Raizada. It sounds so good whenever he calls her KKG or Khushi or KKGSR.
http://www.youtube.com/watch?v=rRH8f3LFc9M
[YOUTUBE]http://www.youtube.com/watch?v=rRH8f3LFc9MC[/YOUTUBE]