Morgan Wallen Steps Out with KT Smith and Son, Squashing Feud Rumors

Morgan Wallen's squashing rumors he's feuding with his ex, KT Smith ... hangin' out with Smith and their son Indigo in the first photos taken since his arrest.

The singer-songwriter stepped out in Nashville in a casual outfit ... t-shirt and jeans just days after cops arrested him for allegedly tossing a chair off the roof of a popular Nashville bar.

KT's also dressed in a causal outfit ... great for running after their little one, Indigo -- who's turning four this summer. She's holdin' the little dude in some pics and just tryna keep up in others.

Looks like a sweet outing between the co-parents -- a pretty stark contrast from the rumors Morgan's totally pissed about how Smith recently married her partner, Luke Scornavacco.

ICYMI ... KT announced her engagement at the end of last month -- before surprising her followers just a couple days later with a signed marriage certificate -- confirming she and Luke eloped.

So, when Morgan got arrested Sunday night and booked on three felony counts of reckless endangerment and one misdemeanor count of disorderly conduct, many fans pointed to the news of her marriage setting him off.

KT herself told The Daily Beast she didn't believe news of her engagement set Wallen off ... saying she'd seen no evidence to prompt that conclusion.