One of my favorite headcanons, is Sousa genuinely thinking Coulson was Daisy's dad for at least a bit there
As soon as I watched s7ep5 for the first time, and the scene near the beginning where Daisy calls Coulson "dad", this headcanon formed. Cause one of my favorite things about that scene, is how NONE of them (Couslon, May and Sousa), reacted when Daisy said that. Which for Coulson and May is whatever, since it was obviously a joke by Daisy and they've known each other for awhile
But I can't help but think of Sousa just assuming after that, that Coulson was Daisy's dad. Because Sousa just met these people. He doesn't know them or their dynamic with each other. If I met this team of people and one of them called the other "dad" and nobody reacted like this was abnormal, I'd just assume they were actually father-daughter. Sousa has no reason to assume otherwise, lol
I like to think that Sousa just rationalized this to himself. Obviously these people are a team- with SHIELD nonetheless. This is there job, so it makes sense that Daisy addresses Coulson the same way everybody else does and not by dad (but it was just them four when she did "slip up" so that just solidifies this for him). And Johnson is a pretty genertic last name (versus Coulson which is not), so maybe Daisy just uses that to hide a connection between them
Sousa just rolling with this and starting to refer to Coulson as Daisy's dad, when talking about him in casual conversation between them. Daisy just going along with it, because it's close enough. Kora also going along with it because she knows what Coulson means to her sister, and Daisy's not saying anything about it so whatever. Sousa realizing Daisy's still calling Coulson "Coulson" when it's just them hanging out together, and worrying Daisy doesn't feel comfortable enough to drop the cover and call her dad "dad" with him there. Daisy now confused as fuck, wondering what is happening. Daisy then having to have a LONG conversation with her boyfriend, that Coulson is in fact not her dad
That last part contradicts a bit with canon, as I'm sure Daisy explained her background to Sousa after everything with Jiaying and Kora. But just pretend :)