“If you are married and you are not having better sex, you are doing something wrong,” says comedian Mitch Fatel.Fatel spent decades talking about his sexual adventure, and the pursuit of them — until he got married. Now, married to a bisexual free spirit, Fatel is a carnal crusader.In this episode of “The Big Questions,” Fatel talks about how reality TV gets marriage wrong, what he’s not allowed to say and why he’s not sad to see David Letterman retire.Below is an excerpt of our talk, but the entire conversation — in which Fatel talks about handling hecklers, his writing process and yes, more sex — can be downloaded via iTunes, SoundCloud or streamed on YouTube.“The Big Questions Podcast” is part of the Sun-Times Media Local Podcast Network.