Seth Rogen finds it ''depressing'' that he's never smoked cannabis with James Franco.

While the pair starred alongside each other in hit 2008 stoner comedy 'Pineapple Express', the comic admits his hunky pal refrains from smoking the narcotic, but other stars such as Jonah Hill and Paul Rudd have joined him in lighting up.

In a candid interview with 'Watch What Happens Live', Seth said: ''This is really depressing for me to say ... I've never smoked weed with James Franco because he doesn't smoke weed. That's why he's such a good actor! It's really sad, actually.''

Quizzed who he has smoked the drug with, Seth revealed comedienne Sarah Silverman and 'Ant-Man' actor Paul have joined him ''lots of times'', while Oscar-nominated 'The Wolf of Wall Street' star Jonah has smoked with him a ''few times''.

But Seth wasn't able to convince his legendary 'Guilt Trip' co-star Barbra Streisand to join him for a smoke.

He lamented: ''No, but we talked about it a lot. She smoked weed with Peter Sellers, though. That's the craziest s**t ever!''

The 31-year-old actor has even enjoyed marijuana with notorious weed lover, Snoop Lion.

He added: ''Yeah, actually I have!''