He's got no idea Bill is jealous. They're going to be nothing at all like their weird domestic parallel selves, which means avoiding all of that. Besides, it's not like he and Iris are going to be a thing, she has a boyfriend, so it's cool. Everyone here's cool. No one's pining, not at all. Everyone has themselves completely under control.

"Wait, what else are you working on? Why would I help you with anything besides getting on the bridge?!"