This week, fans have seen Chas (Lucy Pargeter) pop the question to Carl and falsely claim she is expecting his baby - prompting him to commit to a long-term future with her.
However, unbeknown to Carl, Chas's actions are a complete façade as she is plotting revenge following her discovery of his secret affair with Eve Jenson (Suzanne Shaw).
Speaking to Soaplife about the storyline, Lister explained: "He'll be gutted if Chas has the balls to go through with her revenge plan - and it won't just be his pride that's hurt... He was thrilled when Chas said she was pregnant. He's really happy about the baby. He wants to give Chas whatever she wants - a big Christmas day wedding, anything to make her happy."
The actor continued: "He realises his fling with Eve was a massive mistake, based on excitement and lust. He wants to become a proper family with Chas and the baby. He'll be devastated if it all comes crashing down."
However, asked whether he feels sorry for Carl, Lister replied: "I don't. He's behaved appallingly and he's been a complete fool."
Emmerdale's Chas, Carl and Eve storyline is expected to reach its climax in the soap's Christmas Day episode.