Emmerdale spoilers follow.
Emmerdale's Mackenzie Boyd shocks Charity Dingle next week with an angry threat to end their marriage.
Mackenzie gives Charity a heartbreaking ultimatum as he refuses to accept her decision to become a surrogate for her granddaughter Sarah.
Today's episode sees Charity unexpectedly make the offer, realising that there aren't many other options for Sarah to become a mum.
Charity makes it clear to Sarah that she doesn't plan to tell Mackenzie anytime soon – but her desire for secrecy soon backfires…
Related: Emmerdale's April Windsor stuns Marlon with bold future plans
What to Read Next
"When Eric finds out what's going on thanks to Jacob's involvement, he can't resist passing the details onto Mack to throw a spanner in the works," our Emmerdale source explains.
"Not only does Mack disagree with Charity's surrogacy plan, he's livid after being left in the dark by everyone.
"There's an explosive argument between the couple, as Mack can't believe how fiercely Charity is defending her decision."
Eric's dramatic intervention causes fireworks all round, as Jacob is hurt by his grandfather's decision to betray his confidence by telling Mack.
Related: Emmerdale's Robert to uncover major clue which exposes John's lies
Jacob at least hopes for an apology, but Eric stands his ground by warning that he's making a big mistake.
Sarah speculates that Eric meddled because he has a personal problem with Charity. Eric insists that his main concern is Sarah's shortened life expectancy and what this would mean for the baby.
Meanwhile, the reasons for Mack's unhappiness are explored in more detail. He's hurt that Charity is so excited to carry Sarah's baby but won't entertain the idea of having a child with him.
Watching so much tension and chaos unfold around her, Sarah quickly starts to have doubts…
Related: "He abandoned him" – Emmerdale's Paddy to face painful guilt over Bear
"Sarah doesn't want Charity and Mack's marriage to be destroyed because of her," our insider adds.
"Although Sarah's dream of becoming a mum means everything to her, she couldn't forgive herself if it led to Charity and Mack breaking up.
"Sarah offers to forget about the whole thing, but Charity dismisses her and insists that she can talk Mack round."
Charity's confidence may be misplaced, though. In the end, Mack ups the ante by warning Charity that she needs to choose between the surrogacy or their marriage. How will she respond?
Emmerdale airs on weeknights at 7.30pm on ITV1, and streams on ITVX.
Read more Emmerdale spoilers on our dedicated homepage
Digital Spy's new print issue is here! Buy Oasis - Live in '25 in newsagents or online, now priced at just £8.99.
