"She's the love of my life. I want to marry her. I'm going to go get her," the handsome man tells Arie during a face-to-face conversation.
While Arie is dressed casually in a T-shirt and jean during the meeting, Becca's ex is wearing proposal-worthy a dress shirt and suit.
"If Becca were to leave, I would just be crushed," Arie notes.
The clip also shows Arie admitting, "I've had my heart ripped open, and I don't know how this is going to end."
[Spoiler Warning: Please stop reading now if you don't want to learn the man's identity as well as spoilers for what happens when he begs for Becca back].
While ABC's clip didn't identify him by name, the ex-boyfriend who crashes The Bachelor set is Ross Jirgl, according to prior spoiler reports.
As fans recall, Becca said she was in an on-again, off-again relationship with her former love for seven years.
It's unclear how long before Becca appeared on The Bachelor that she split once and for all from Ross, who currently works as a sports performance coach for the Stanford University football team.
Becca told Arie that she struggled to leave her tumultuous romance in the past because he had helped her through the difficult days of her beloved father's passing from a brain tumor when she was 19 years old. Becca, however, insisted to Arie she was over that guy and ready to move forward with her life.
Ross will appear on The Bachelor during the season's final days in Peru, just before the final Rose Ceremony.
Ross will approach Becca about getting back together, and according to Reality Steve spoiler blogger Steve Carbone, he will propose marriage to the bachelorette!
However, Becca will allegedly reject Ross' proposal and choose stay on The Bachelor path. She picks a chance with Arie over marriage with her ex.
Becca and Ross reportedly met in college when Ross played football for the Division II football team at Minnesota State University, which they both attended. Ross graduated from the university in 2013 with a degree in biomedical science.