In a sneak peek of the second episode, Rachel Lindsay comes face to face with a woman who claims to be DeMario's girlfriend.
In the preview, Lindsay, 32, is informed that DeMario was still romantically involved when he agreed to appear on the show.
"This girl Lexie says she's in a relationship with DeMario and he disappears for a couple of days and the next time she's seeing him is on After the Final Rose, meeting me," Lindsay said in a confessional. "I am completely taken aback."
Ultimately, Lindsay pulls DeMario away from the rest of the contestants and brings him face-to-face with his estranged girlfriend.
To see how their interaction unfolds, watch the video above.
"The Bachelorette" airs on Monday nights at 8 p.m. ET on ABC.