Dill Mill Gayye S14 E70 Armaan's Prank On Siddhant

Armaan plays a prank on Siddhant citing Riddhima's likes. He makes Siddhant wear a pink shirt. Later, he makes Siddhant wax his body and play basketball. Riddhima notices this and finds it strange. When people poke fun at Siddhant, he gets upset. Why does Armaan play this prank?