EastEnders spoilers follow.

EastEnders star Perry Fenwick has explained why Billy will be so heartbroken over the secret in the Mitchell family.

It’s been a tumultuous few weeks for the family, with Billy recently discovering that his father, Stevie, had a whole other family that he didn’t even know about.

This is compounded when Stevie revealed that Billy’s mother, Val, had passed away long ago, with the character attempting to leave Walford after seeing the rift it caused.

Fenwick, who has played Billy since 1998, has spoken about the dramatic developments, outlining his character’s reaction to the news, which comes after Phil disrupts Stevie’s birthday party.

Related: EastEnders’ Nish delivers cruel Priya twist in iPlayer release

“The fact it’s Stevie’s birthday also makes Billy think of his mum, who shared the same birthday as his dad. He’s thinking: ‘Oh wow, wherever Mum is, it’s her birthday too.’

“It’s strange that Phil is always brooding in the background with Stevie. Of all the people you’d think should have a problem with Stevie, it should be Billy, not Phil. But Phil hates Stevie with a passion, and nobody knows why – maybe he’s jealous.

“But Phil keeps doing detective work on Stevie because he’s sure he’s going to find something, and he does. They leave the party, and Phil makes Stevie tell Billy that his mum died and the circumstances surrounding her death. It’s absolutely devastating for Billy because the news she’s dead is hard enough, but there’s much more to it.

“Phil might argue that he’s protecting Billy, but he’s not thinking about Billy when he gets Stevie to break the news like that. For all Phil knows, it could send Billy over the edge because it’s completely screwed up everything he’s got. What Billy thought he knew about his mum has been blown out of the water.

Related: EastEnders announces Chrissie Watts return this autumn

“Remember, he’s found out over a couple of weeks that he’s got a half-brother [Teddy] and two nephews [Harry and Barney], and now that his mum is dead. It throws him completely. Billy has got so many years of hurt and neglect behind him. In this situation, he’ll do anything to protect himself and his family from any more distress. It’s a hell of a lot to take in.”

It’s not the only secret that will be revealed at the party, with Billy also discovering that Phil made Will lie about Stevie stealing the money from the fundraiser – a move that drives a wedge between the pair.

“It’s bad enough that Phil couldn’t let sleeping dogs lie with Stevie, but now he’s used Will to stir the pot. Phil’s been standing there watching all of this unfold and enjoying the turmoil he’s caused while saying he’s doing it for Billy.

“But what doesn’t kill you makes you stronger, and Billy is gaining strength through all this. Phil’s opened Pandora’s box and he can’t put the lid back on it. Over the years, we’ve seen Billy and Phil have proper disagreements, but this week, they have their ‘High Noon’ moment, and for once, Billy calls the shots.”

The developments come just as Stevie was growing closer to Billy through his relationship with Will and Janet, with Perry explaining: “Billy has been so anti-Stevie since he arrived because of the appalling parenting he had when he was growing up. His childhood really marked him for a lot of his life, and before Stevie turned up, I think Billy probably just presumed he was dead.

Related: EastEnders gift guide – all the best merchandise

“However, Stevie has turned up, and he won’t go away, and Billy’s kids love him! So I think Billy has seen that he’s really trying and decided he can only be angry with Stevie for so long. Stevie is very good with them and they think he’s this wonderful, charming granddad. Honey keeps telling him that he should make an effort with Stevie for them, so Billy thinks, if it makes them happy, it makes me happy.”

Whilst the dramatic storyline will certainly have a lingering effect, Perry paid testament to his co-stars, with Alan Ford, Roland Manookian, Elijah Holloway and Lewis Bridgeman all receiving praise for their performances as Stevie, Teddy, Harry and Barney respectively.

“I’ve known and admired Alan for a long time – he’s a real-life East Ender,” Perry said. “Years ago, I saw him do a one-man show, and he’s incredibly funny, and he reminds me of my dad in real life.

Related: Best streaming service UK 2024

“I was thrilled to bits when they cast Alan as Stevie because, for me, there was only one actor who could play Billy’s dad and that’s Alan Ford. Throughout this whole storyline, Alan has been brilliant, and everybody loves him.

“Roland, Elijah and Lewis are beautifully cast, and they’ve just stepped into Mitchell shoes perfectly. That chemistry between them and the rest of us as Mitchells is there already, and they’ve given the family an injection of fresh energy.”