The 20^th episode of "Big Bang Theory" season 9 will be all about revelations and jitters.

In the episode titled "The Big Bear Precipitation," secrets will be revealed as Amy Farrah Fowler, Sheldon Cooper, Penny and Leonard Hofstadter go on a cabin trip for the upcoming weekend. Spoilers for the episode reveal that it is Sheldon Cooper who will spill the beans about the dark secret of Leonard, but fans have yet to know what this "dark secret" is all about.

Meanwhile in Pasadena, Howard and Bernadette will have to deal with certain issues. Based on the trailer for the upcoming episode, it seems that their clingy friend Koothrappali is going to be too much excited for Bernadette's upcoming baby that she would inadvertently extend his welcome yet again. His crazy third wheeling will stop as Howard and Bernadette finally decide to draw the line and let Koothrappali know he is already biting off too much.

According to Yahoo!, the baby detail in the Valentine's Day episode of "Big Bang Theory" was a last minute addition to the script.

"We were writing that Valentine's Day episode and there was no baby in the outline. There were four or five of us in the writer's room on a Saturday afternoon and we were at the end and just thinking of ways to finish the episode. I just said, 'I don't even know why I'm pitching this, but what if Bernadette says to the rabbit, 'I'll find another time to tell him I'm pregnant.' A quiet fell over the room and then several writers were like, 'Oh my god, can we do it please?! That's so amazing!' And I said, 'Screw it, let's do it. Type it! Have her say it.' And that was it,' shared "The Big Bang Theory" executive producer Steve Molaro.

Fans of the series expect the upcoming Wolowitz baby to cause more trouble and mirth to the whole gang.

Written by Chuck Lorre, episode 20 of "Big Bang Theory" episode 9 will air on Thursday, April 7, 7:00 P.M. on CBS.