'Bachelorette' Rachel Lindsay Comes Face to Face With [SPOILER] After Their Devastating Breakup

What's wrong with Peter Kraus?

Viewers finally found out on Monday's season finale of The Bachelorette, after his and Rachel Lindsay's devastating breakup.

WATCH: Who Does Rachel Lindsay Pick on 'The Bachelorette' Finale? 7 Clues That Might Reveal the Lucky Guy!

Though Peter made the final two, after Rachel delivered a strict line about being "here for a proposal" during the rose ceremony, the two just couldn't see eye to eye on the engagement issue.

The two had fun on their day date, but things got serious at night, when Rachel brought up a proposal again, and Peter admitted that he was "in love" with her, but couldn't get to the point of proposing the next day. Rachel didn't want to settle for seeing how things would work, and he didn't want to compromise, and at the end of the night, they said goodbye (with an emotional makeout session that ended with Peter telling Rachel that she was settling "for a life of mediocrity" and she knew where to find him if it didn't work out).

IT. WAS. DEVASTATING.

After leaving things less than settled, Peter and Rachel finally came face to face on After the Final Rose, where they opened up about the "hard" way they ended things.

"I knew this was going to be a hard experience. To go from the way that we parted to complete silence was hard to see it just brought back... I'm shaking like a leaf," Peter confessed.

EXCLUSIVE: 'Bachelorette' Rachel Lindsay Talks Tearful Fight With Peter, Addresses Bryan's 'Player' Past

"I mean, it is hard. That was hard to watch. It was hard being there in that moment, and it was frustrating. I was confused in that moment. I didn't understand how you could come that far... In Geneva, you promised me that if this wasn't what you wanted you would leave," Rachel replied. "I was confused as to why you were still there... you wouldn't take the actions to make that future happen with me."

"The whole focal point on us was that you couldn't propose, but there were other deep-rooted issues for me," Rachel continued, as Peter expressed his "frustration" and said that he felt "attacked."

"I was incredibly emotional at the time, and I watched you walk out the door and I knew you were a person I could spend the rest of my life with... I let you go because I couldn't get to that same point as you at that point, and all I could think is what was wrong with me?," he explained. "I sill wonder what could have happened differently."
"[But] I definitely felt that was the end. I did ask if I could reach back out to you, and the answer was no," he said.

Rachel and Peter left their reunion wishing each other "the best."

WATCH: 'The Bachelorette': Rachel's Family Calls Peter the 'Winner' -- So Why is He in Tears Before Fantasy Suites?

"Mostly thank you for giving me a chance. You allowed me to stay as long as you did, and that gave me an opportunity to get the feelings that i did.... though things didn't end the way that I hoped, I have you to thank for the feelings that I did have, so I wish you nothing but the best."

Things may not have worked out between Peter and Rachel, but could Peter be our next Bachelor? Find out in the video below!