The 27-year-old former football player tearfully said goodbye to frontrunner Cassie Randolph after she broke up with him, confessing to her that he was in love with her and that he wanted it to be her at the end. Though he still has two women left in the picture -- Tayshia and Hannah G. -- a proposal seems likely. And according to former Bachelor Ben Higgins, it shouldn't happen at all.
"He only wanted Cassie," Ben told ET, arguing that Colton's fence jump proves this. "I don't know, at this point, how he looks around himself and goes, 'Yeah, the other two women still have a chance.'"
"I don't think it would be fair to them, especially after we watched what just happened.. [for Colton to end the show] with an engagement," he added.
While an engagement-less Bachelor finale seems out of the ordinary these days, roughly a third of Bachelors actually haven't gotten down on one knee. From our very first Bachelor, Alex Michel, to our most recent noncommittal lead, Juan Pablo Galavis, here's who Underwood could join on the list of Bachelors who didn't propose.
Season 1: Alex Michel (2002)
Trista Sutter (nee Rehn) became our first Bachelorette after she was dumped by Michel on the season one finale of The Bachelor in 2002. Michel ended up not proposing to Amanda Marsh either, but they did agree to start a relationship. That relationship ended after several months.
Season 4: Bob Guiney (2003)
Between Estella Gardinier and Kelly Jo Kuharski, Guiney decided that Gardinier was a better match for him, but didn't propose. Instead, he offered her a promise ring and the request to keep dating. They broke up shortly after the season aired in 2003.
Season 5: Jesse Palmer (2004)
Season five, starring Palmer, saw a similar ending, with the Bachelor choosing Jessica Bowlin over Tara Huckeby. They continued to date after she earned his final rose, but broke up several weeks later.
Season 7: Charlie O'Connell (2005)
Fans had hope that despite the lack of a proposal, O'Connell and his final pick, Sarah Brice, might actually last. He chose her over Krisily Kennedy in his 2005 finale, however, they broke up in 2007. They reconciled in 2008, but called it quits for good two years later, in 2010.
Season 8: Travis Stork (2006)
Stork didn't get down on one knee either during the season eight finale of The Bachelor in 2006. He gave his final rose to Sarah Stone over Moana Dixon, and the two began a relationship. They broke up shortly after the show aired.
Season 9: Lorenzo Borghese (2006)
Borghese was our first switcheroo-loving Bachelor, as he chose to continue a relationship with Jennifer Wilson after the show. They broke up months later, in January 2007, before he dated his runner-up, Sadie Murray, though they split in March of that year.
Season 11: Brad Womack (2007)
Womack made Bachelor history in 2007, when he not only decided not to propose, but also decided not to pursue a relationship with either of his finalists, Jenni Croft or DeAnna Pappas. Eesh!
Season 18: Juan Pablo Galavis (2014)
After a string of finale proposals (and subsequent breakups), Galavis shocked audiences when he said goodbye to Clare Crawley, choosing Nikki Ferrell instead -- but not proposing. The single dad wouldn't even say he was in love with Ferrell, so the pair's breakup in October 2014 didn't come as much of a surprise.
"Neil Lane put it in the box," Underwood continued, confirming that he met with the celebrity jeweler on set of The Bachelor. "I have met Neil Lane, yes... during filming."
Only time will tell if that ring ended up on someone's finger, however. Underwood's two-night Bachelor finale airs on Monday and Tuesday at 8 p.m. ET/PT on ABC. Join ET's Bachelor Nation Facebook group here.