James Franco has made a sex tape.

The 'Rise of the Planet Of The Apes' star has confessed he and an ex-girlfriend decided to film themselves making love, but they were disappointed with the results when they watched the footage back.

During an interview on 'Conan' on Tuesday night (09.08.11), he revealed: "When I was young, it's not like I went down to Van Nuys and tried to break into the porn industry, I got a video camera and my girlfriend and I decided to film ourselves. And we watched it back and said, 'Yeah, let's never watch that again.' "

James' one-off foray into X-rated home entertainment gave him a renewed respect for porn stars.

However, his attempts to explain his admiration for adult actors by mentioning his grandmother didn't go down well with host Conan O'Brien.

As James was saying, "those people in the pornos, they are great performers, they're not just doing it they're selling it to an audience and just like, you know, let's say my grandmother..." the interviewer jokingly leapt from his seat and ran off the set.

But the 33-year-old actor saw the funny side and laughed along with the studio audience.

James' next role will see him play a cocaine-addicted lawyer who embarks on a relationship with a naive porn star portrayed by Ashley Hinshaw in 'Cherry'. Heather Graham also stars as an adult movie director.