He explains why.
"We want to reach as many people as possible. It's very close to an R, believe me, it's right there. But I think we owe it to the next generation. We thought we'd join that club for a while."
Sylvester Stallone also went onto talk about overcoming the competition set up in the 80s amongst him and his co-stars, most notably Arnold Schwarzenegger.
"[We] are almost like Ali and Frazier. Thank God for Arnold because he made me work harder."
Arnold Schwarzenegger added,
"Sly was one of my heroes. Even though we were very competitive, they were inspirations for me. We would call each other and say, 'I just killed this many people, how about you?'"
Sylvester Stallone continued,
"We are children with arthritis, we are young forever. I think if you wake up in the morning and your ass falls off, it's time to retire."
Sylvester Stallone then went onto explain the difference between the first two movies, and this new sequel, describing the tone as more serious this time out.
"With the first one, I didn't know which direction to go. It was experimental, more dramatic and heavier. In the second one, I think we went too far in the comedy and one-liners. (For the third film) I realized we should get back to being more dramatic. When men and women know each other, there's a kind of human comedy, not jokes, but when the action starts I don't like to do jokes. So, I believe we finally got it right on the third one. It's kind of like marriage."
He also commented on working with his new director Patrick Hughes, best known for his action thriller Red Hill.
"Directors and actors are giving audiences what they want. I think we are exactly where we should be...We belong to a different generation so we do what we understand... I believe it's all a matter of evolution and eventually it will revert back."
Patrick Hughes himself had to say this about the movie.
"It's a big fat piece of popcorn."
The Expendables 3 comes to theaters August 15th, 2014 and stars Sylvester Stallone, Jason Statham, Jet Li, Antonio Banderas, Wesley Snipes, Dolph Lundgren, Mel Gibson, Harrison Ford. The film is directed by Patrick Hughes.