Lord Krishna played flute during the night time prior to Ras Lila. When all the Gopi's came to Vrindavan, Lord asked them to go back and fullfill their Duties.Why?

Upon listening this Gopi's told Lord about their Kama Bhava towards him. It is written in Shrimad Bhagvat that in the following nights Lord played with them(RASLILA) and during that he touched Gopi's body, smiled at them, touched their feet to each other etc. This creats lot of Kama Bhav while reading itself then what actually must have happened then is a question? How Lord can indulge in such worldly pleasures or can give such pleasure to others ?