Sammy boy if u really loved that girl you would have told her to hold off the kiss till the day she was single Aniways I guess he had his eyes on the prize and was willing to do anything to get it.
P.S.
In my opinion they were taking singing lessons at the hotel for 2 hours. Since Sheetal thought sammy was a horrible singer she wanted to do him a last favor and a better singer would make for a more datable guy :P :P.