Gerardo Mejia, Kathy Mejia Gerardo Mejia, Kathy Mejia

One-hit wonders Gerardo (of "Rico Suave" fame) and Sisqo (best known for "The Thong Song") trade spouses on Sunday's episode of Celebrity Wife Swap — and immediately, Sisqo's girlfriend Elizabeth realizes that she might be getting more than she bargained for.

When Elizabeth was wandering around the house trying to figure out which celebrity she had been matched with, one of Gerardo's dogs was upstairs locked in a bedroom, he tells And let's just say, when you gotta go, you gotta go.

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"They closed him in upstairs," Gerardo explains. "So when I come in and say hello to her and I'm showing her the house, there's just tons of poop. ... And the thing is, it's the little dog, and the little dog's my wife's dog. So I was like, that's not my dog. So my new 'wife' in the house had to clean up that mess. I don't think she really enjoyed that part of it."

Judging from the exclusive clip below, it's a safe bet she didn't.

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And that wasn't the only thing Elizabeth and Gerardo clashed on during their week together. Other points of contention included the singer's 17-year-old daughter's curfew time, his "open-door policy" of welcoming people into his family's home, and his penchant for walking around the house shirtless.

"My new wife is telling me, 'Put your shirt on now. You're not Rico Suave anymore,'" Gerardo recalls. "That was funny. ... At the end of the day, we had a really good time."

Celebrity Wife Swap airs Sunday at 8/7c on ABC. Check out an exclusive clip from Sunday's episode below.