The actor also drops a few hints about season 5.

Season 4 ofThis Is Usended with a brutal fight between two-thirds of the Big Three.

(The grown-up version was revealed in the episode).

This Is Us - Season 2

Credit: Ron Batzdorff/NBC

Dont these two have their hands full already?

At least that has been historically the case.

I guess we’ll find out.

We know they have this conversation and we know that Jack has a sister.

So we will now wait and see how theThis Is Uswriters connect those two dots.

And then now we get to enjoy the story of how these two dots get connected.

Not that this adoption journey in the hit family drama’s fifth season will be all balloons and avocados.

There’s going to be struggles around it, he warns.

I’m sure there will be individual personal feelings between Toby and Kate.

I’m sure her family will have thoughts.

Well see how the writers handle it, but I can guaranteeconflict!

Which leads to more questions about the couple, of course.

Sullivan hints that season 5 will explore the longterm health of Toby and Kate’s relationship.

That should be welcome news to fans who have been speculating about Kates status down the road (divorced?

And there is no straight line from point A to point B.

There’s just not a lot that we either know at this point or can share.

Does he know now?

Still dont, says Sullivan.

And I keep forgetting to ask.

In fact, I hadn’t thought about that a long time until you just brought it up.

It’s fun for me over the next two seasons to still have that little mystery.

I walk onto set and somebody says Here, this is what you’re bringing to the house.

It’s way more fun for me to just say Fantastic.

Okay, Instead of Wait, why?

I need to know.

I don’t need to.

I just hand it to Sterling and [say], Heres the sidewalk chalk you wanted….

I know everything I need to know to tell my part of the story.

Sometimes it’s helpful for me to pick and choose the things that I’m aware of.

If Toby is not aware of it, then maybe I don’t need to be aware of it.

Sometimes the grandparents aren’t there for the delivery or postpartum scenarios.

So I don’t think there’s too much to read it.

There is never too much to read into until there is.

On that note, lets read too much into something for a minute.

How would Sullivan feel if Kate and Tobydidntwind up in forever bliss?

They’re not going to force these characters into any kind of salacious scenario for the sake of drama.

These are well-lived, well-written characters who are headed exactly where they’re supposed to be.

Their journey will take them through the recent real-world events, as confirmed by Fogelman.

And finally, how about a cryptic hint about Toby in the episodes to come?