Katy Perry jokes about BFF RiRi's pot smoking tendencies

Katy Perry has taken a playful jab at her close pal Rihanna, about her marijuana use and Instagram obsession.

Perry said in an interview with Elle Canada that she thinks the 'Umbrella' hitmaker always looks fresh despite of smoking pot, Us magazine reported.

The 'Roar' hitmaker also joked saying that she was amazed at how Rihanna managed to stay fresh when she doesn't sleep and is on Instagram till four o'clock in the morning.