Going into the finale in Thailand, Sean, 29, was still undecided. But by the end of Monday's two-hour finale, he had made his decision.
After introducing both women to his family and going on one more romantic date with each of them, Sean proposed to graphic designer Catherine, 26, in the emotional season finale.
"I think the world of you and I miss you every time we have to say goodbye. I don't want to say goodbye anymore," he told her. "Catherine, I want to spend the rest of my life telling you, 'I love you,' and making you feel like the most special, beautiful woman in the world."
Then, he got down on one knee and asked, "Catherine, will you marry me?" Her hands were shaking as he presented a 3-carat, cushion-cut, micropavé Neil Lane diamond ring, which she giddily accepted.
"Is this for real?" she asked. "I'm so happy ... I am so grateful to have met somebody like you. I've never been so comfortable about myself and with somebody."
Saying GoodbyeIt was a joyful moment that followed a very difficult one, when Sean broke the news to Lindsay and said goodbye.
"I want to give you my heart so bad. But my heart is leading me somewhere else," Sean told her. "I've been so confused and I've been searching for clarity and praying for clarity. Now I think I've finally gotten it. I have to say goodbye to you. And it's by far the hardest thing I've ever had to do because I know how incredible you are. And I love you. That's the hardest part. I love you. I know I do. I'm sorry."
At first, Lindsay was speechless, saying only, "It's okay." But as the news sunk in, she started to cry and told him, "I'm going to go 'cause this is just really, really painful. This is my nightmare. I really didn't see this coming. I'm happy for you. I'm happy that you found love. But I honestly can't imagine my life without you and that's something that I'm going to have to figure out."
Following their goodbye, another heart-pounding moment arose as Sean prepared to see Catherine, when host Chris Harrison handed him a letter she had written.
Mystery LetterSean nervously read the letter, which contained exactly what he was hoping to hear. "I'm so excited to build our own family together ... I truly believe we are perfect for each other," she had written. " I can't picture myself as anything but your wife ... All I want to do is move to Dallas and become part of the wonderful family that you have and build our own ... I will love you for always."
And moments later, a beaming Sean cast his eyes towards his future bride as she walked toward him down the path.
Following the proposal, an elated Sean and Catherine ended their Bachelor journey with an elephant trek through the Thai jungle. From atop the elephant, Catherine yelled, "This is the best day of my life!"