'90 Day Fiancé' Recap: Usman Proposes to Kim But Their Marriage Plans Are Illegal (Exclusive)

Usman proposed to Kim, but the couple hit a major snag in their plans to get married.

Usman and Kim have hit a major roadblock in their plans to get married. On Sunday's episode of 90 Day Fiancé: Happily Ever After?, Usman proposed to Kim even though she already proposed to him and he accepted, but their lawyer noted that they can't legally marry in the United States if they continue with his plan to have multiple wives. 

Kim has already agreed that Usman can have multiple wives, though she insists on being the first wife. After his mom reluctantly gave her blessing earlier this season on the condition that Usman can still have younger wives who will give him children, the couple seemed on track to tie the knot. On Sunday's episode, Usman surprised Kim by proposing to her. Although Kim previously proposed to Usman, Usman said he wanted to do it and got down on one knee while she helped him decorate his house in Nigeria.

"Kimberly proposed to me, I appreciate it, I understand how much she loves me. But that is not the ideal way," he told cameras. 

Kim cried as Usman put a diamond ring on her finger.

"It just drives it home for me that this man loves me just as much as I love him," she told cameras. "And I feel like all of the fights, getting the blessing, this is what it comes to now. This is what made it all worth it."

Kim and Usman said they wanted to get married in the United States, but Usman insisted that he didn't necessarily want to live there since his music business is in Nigeria. Still, Kim was excited for Usman to experience life with her in the U.S. However, they got a dose of reality when they spoke to an immigration lawyer about getting the K-1 visa process started. Usman said he wanted to come back to Nigeria every three or four months, and the lawyer said it wasn't possible until he got his green card and got permission to travel. Then when Kim said Usman was planning to have multiple wives, the lawyer told them polygamy was against the law in the U.S. and that Usman could lose his green card if it was found out that he was polygamous. She bluntly told him he could only be married to one woman after getting a green card. Kim admitted they should have consulted with an immigration lawyer sooner.

"If Usman can't take a second wife, I don't think he'll marry me because this is not what his family wants, this is not what he wants," she said. "I mean, he wants to have children, that's what this whole second wife thing is about. ... I really hope that we haven't come this far just to hit a dead end."

Usman added, "If the law is coming in between us, I don't know what we're gonna do right now."

ET recently spoke with 52-year-old Kim, who candidly spoke about how fans' criticism affects her and responded to those who think she's "delusional" when it comes to her relationship with 33-year-old Usman. Watch the video below for more.