ET recently spoke with the pair at The CW's upfront presentation in New York, where they shared their thoughts on the cherished show coming to an end after its whopping 15-season run, admitting that they aren't looking forward to saying goodbye to the Winchester brothers.
"We don't know [the ending] yet," Padalecki admitted, adding, "I think, to a certain degree, the fandom won't be happy with any ending. Nor will we, to a certain degree. I don't think any of us want to see this show go."
In March, it was announced that the hit CW show will draw to a close after the upcoming season. However, as Ackles explained to ET, after years of playing Dean Winchester, he believes the character will always be with him on some level.
"I don't think we'll ever say goodbye to these characters," he stated. "I mean, really, living with them for 15 years…is only the start… I think it was Stallone that said that 'to the greatest imaginary friend I've ever had' talking about Rocky Balboa and I kinda feel the same way. These guys will live with us forever."
In creating the final 20 episodes of the show, which features the brothers regularly squaring off against all manner of outlandish creatures, including ghosts, monsters and demons, Padalecki explained they aim to give their longtime fans what they want -- an entertaining, engaging ending.
"Trying to do the show justice," he shared of his mindset going into the final stretch. "Trying to do these characters some justice and honor the legacy that was Supernatural. You know, the writers and the directors and the actors and actresses and producers and our network and our studio, and trying to do well by the fandom."
It was the pair, and actor Misha Collins, who plays the angel Castiel on the series, who officially announced that the 15th season would be the last in March. They broke the news with a video on social media.
"We just told the crew that though we're very, very excited to be moving into our 15th season, it will be our last. Fifteen years of a show that has certainly changed my life. I know it's changed these two guys' life," Ackles explained, referring to Padalecki and Collins. "And we just wanted you to hear from us that though we're excited about next year, it will be the finale. The big, grand finale of a new institution."
"We've cried some tears and we'll cry some more..." Padalecki said, trailing off, prompting Ackles to add: "But we're going to save the emotion for next season."
"We're grateful, but we'll work all the emotion in next season," Padalecki promised.
Season 15 of Supernatural will air in fall 2019 on The CW.
Check out the full chat with Padalecki and Ackles up above.