Article continues below advertisementDemi Lovato has some regrets about her past romance with Wilmer Valderrama.During the Tuesday, March 3, episode of the "Baby, This Is Keke Palmer" podcast, the singer, 33, revealed that in retrospect, she looks down on the age gap she shared with her ex, 46.Article continues below advertisementSource: Baby, This Is Keke Palmer/YouTubeDemi Lovato guest-starred on Keke Palmer's podcast."I'm sitting here in this state of mind today, like, grateful for everything that I've been through," she expressed. "It was really challenging.