The Umbrella Academy cast weigh in on season 4's surprise love triangle

Watch: The Umbrella Academy cast speak about Diego, Lila and Five's love triangle:

The Umbrella Academy has never shied away from romance amongst the chaos of the Hargreeves family's quest to save the world from one apocalypse after the next, but sometimes it can be quite the surprise which is the case in season 4.

Warning: this article contains some spoilers for season 4

In the new season, Lila (Ritu Arya) and Diego (David Casta?eda) are having marital troubles after six years spent without their powers in the new timeline the family found themselves in. The couple now have three children and are making do, but for Lila and Diego, there's something missing.

Read more: The Umbrella Academy ending is 'exactly what it needs to be', cast says

When Lila and Diego's brother Five (Aidan Gallagher) decide to investigate the existence of multiple timelines they get stuck for seven years. During that time the two spark an unexpected romance, which follows them home when they eventually make it back.

"You're not expecting it first," Gallagher tells Yahoo UK of the plotline. "But then I view it through the analogy of magnets, like Lila and Five are very much the same thing, they sort of repel each other because of that.

"They've sort of [got] a competitive nature, but then given the right context it flips and it makes a lot of sense. But that's a credit to everyone working on the show, and also this one [Ritu Arya] over here, that it turned out well."

Casta?eda explains that he was aware of the storyline before season 4 started, that it was always the plan to have Diego, Lila and Five experience this love triangle.

"Steven had told me that there was going to be a little bit of triangle dosage," the actor shares. "I mean, playing with Ritu is always lovely because she's always open, wherever I want to go she goes, wherever she wants to go I go.

"So there's a comfort level of taking it to certain spaces that sometimes with other actors you might have to ask, or you might have to get to know them a little bit more and that's what makes her really fun. So I can sort of set myself up to be the punch line of a joke with her but also allow to really go there on these emotional moments."

Arya, for her part, enjoyed getting to explore something different with her character this season, as she reflects: "Lila, in particular, has quite a raw and vulnerable journey, it was amazing getting to play at this time with the added depths of being a mother and having marriage. She's still got her core mischievous side, but I've loved playing her this season."

Read more: ‘The Umbrella Academy deserved a better ending’

Reflecting on Gallagher taking on a new role in the series, he adds: "I thought it was kind of charming to see Aidan step into this romantic lead as he was coming up of age. When we first got to work with him I remember he was 14 when he's making that peanut butter sandwich in the kitchen, you know?

"He was such a kid, and I still remember that day when we were doing that scene."

Justin H Min, who plays Hargreeves sibling Ben, chimes in to say he also often forgets how old Aidan was at the time when they started filming, adding: "I forget how young he looked until I randomly see some clips from season one."

To which Casta?eda joked: "He was a baby, he was a child, and now he's a dawg."

The Umbrella Academy's final season is out now on Netflix.