They booked flights and eagerly shared in planning their trip.
When she saw that one of their dream hotels was having a sale, the blissfully unaware wife wanted to book and emailed her husband to confirm - but he put her off.
When she returned home she found her husband nervously pacing before he delivered a bombshell.
"Everything after that is a blur, but I can picture his face and how nervous he was," the jilted wife told Capsule.
"I was so, so, so, so shocked, but I know I asked him why and he just said, quite coldly, 'because I can see that I'm not in love with you and this marriage is not going to work out'."
She then found herself living back at her parent's house, her life in tatters.
As time went on, she began to notice strange behaviour from her friend group, who began excluding her from events.
She confronted her closest friend and was told the devastating truth - her husband had left her for one of her friends.
They had been close, had been bridesmaids together. She even attended her wedding.
"I think I laughed it seemed so insane to me," Kathryn told Capsule.
It got worse.
Her closest friend revealed that the new couple had gone on holiday and checked into the hotel that was nearly booked by the betrayed bride.
"Now I see him for who he truly is, and I do feel grateful I got to see that before I had children with him," she told Capsule.
"My advice to anyone who has been betrayed is that it does get better. Someone said that to me early on and I couldn't imagine that there would ever come a day when I'd be happy again. But it does happen."