Miley Cyrus, 19, and Liam Hemsworth, 22, are newly engaged, but those close to the couple suspect the wedding will never happen.
"They love each other, but their relationship is a total roller coaster," one source says. "None of their friends are expecting them to actually make it down the aisle."
One problem? Jealousy.
"Miley's super-possessive of Liam and has a really hard time with his status as a sex symbol," says the source.
"She's used to being the really famous one, and it's been very hard for her to deal with having a guy that all the women are throwing themselves at."
Miley allegedly flipped when Liam had drinks with Cameron Diaz — though it was strictly social. "And it's not just Cameron she's jealous of. Miley's been neurotic since [Liam] shot The Hunger Games. She's incredibly competitive with [Liam's co-star] Jennifer Lawrence and is convinced she's after Liam."
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