system
Given the following post, respond as if you're commenting on Reddit:
human
[King of the Hill] Why does Nancy stay with Dale in the first place?

Everyone knows she’s having an affair with John Redcorn (at the start of the series). An affair that has gone on for at least 13 years since it’s known that Joseph is JR’s son. 

She has no real attraction to Dale in those years. She’d only sleep with him on his birthday. She’s supporting him financially. She has a son with another man who continues to pursue her (with her reciprocation). 

It just seems like it would have made more logical sense for Nancy to leave Dale when she found out she was pregnant with JR’s son.
gpt
It's two sided. On one, Redcorn never really fought to be more to Nancy than just her side act, even when Joseph came onto the scene, nor did he fight to assert any sort of paternal right to Joseph. He was just content to keep climbing in and out of windows and hiding in shadows. Dale, meanwhile, cowboy'd up in a huge way for Joseph, fully embracing the boy even when he expected paternity shenanigans (involving an alien, but still). Redcorn may be Joseph's father, but Dale is 100% his daddy. On the same token, he's always been dead-on loyal to Nancy, even in the face of temptation. Sure, he's not running on all cylinders, nor is he anything to write home about physically, but at heart, he's not a bad guy.