Showrunner teases fallout between Sheldon and Leonard's parents in The Big Bang Theory season 10

The Big Bang Theory season 10 will address the events of the season 9 finale, which ended on a cliffhanger. Did Sheldon's mother Mary Cooper and Leonard's father Alfred Hofstadter hook up after leaving the dinner abruptly for a "night cap" at their hotel?

Addressing if this sudden development affects Penny and Leonard's second wedding, showrunner Steve Molaro teased a fallout before the ceremony. He told Entertainment Weekly, "We're left with a good amount of tension between all the parents. There's a lot of fallout the following morning before we even get to the ceremony, if we even do."

Leonard and Penny decided to re-marry in the presence of their family and friends, as they had eloped and got married in Vegas in the season 9 premiere episode. But the way the season ended, the couple's second wedding may hit some roadblocks, or even if the couple do go through with it, the ceremony will surely be filled with awkward family moments.

Previously, Steve Molaro spoke to Entertainment Weekly about the season 9 finale and expanded on Mary and Alfred's sudden move. Molaro shared, "I don't know what happened. I know they were getting along quite well, and left to go to the same hotel for a nightcap, and turned off their phones. The details of exactly what happened, if we even ever find out all the details, will be left for the season premiere of season 10."

Teasing Sheldon and Leonard being "potential brothers" in season 10, the producer explained, "It's inching toward that, isn't it? There was — it fell out of the script — a joke referring to them as potential brothers. I'm going to go with the word "uncomfortable", probably is a good starting place for their primary emotion of where we leave them and where we will pick up."

The Big Bang Theory will return with its 10th season on 19 September at 8pm EST on CBS Network.