Nick Jonas and girlfriend Olivia Culpo were last spotted together in LA, celebrating the release of Nick Jonas' new song for 2014, "Chains." Since then, reports suggest that Nick Jonas and girlfriend Olivia Culpo are having trouble in paradise and may be heading towards a break up.

Two weeks ago, Olivia Culpo, who was former Miss USA 2012, joined Nick Jonas for celebrations following the release of his new song, "Chains."

Instagram photos posted by both Nick Jonas and Olivia Culpo show the two looking young, beautiful, and happy, without a care in the world while they toasted to Nick Jonas' burgeoning successful career.

One photo shows the couple dressed to the nines and boarding a plane. Nick appears to be checking out his gorgeous girlfriend.

"Hey YOU, what are you looking at?!?!? #Cheerstochains #Vegas," she playfully captioned the photo.

Another Instagram picture shows Nick and Olivia toasting with champagne on a private jet on their way to Las Vegas, along with brother Joe Jonas.

Yet another picture shows Olivia in the same dress at a club, partying with her boyfriend.

Since then, not a peep out of either of them about each other, and not a single Instagram photo featuring both of them together. Many fans feared Nick and Olivia suffered a break up soon after their festivities, but RadarOnline.com debunks these rumors.

"Nick and Olivia are together, but they are always on-again, off-again," a source close to Jonas told RadarOnline.com. "They break-up all the time."

"They fight a lot," the source admitted. "One day he says that he is going to marry her and the next day they are not talking."

"Nick is very sarcastic, but this comes across as quite mean to Olivia," the source told Radar. "She is always taking offense to things that he says."

Sounds like these two don't have long before all hell breaks loose. We hope Nick and Olivia can figure out a way to mend their problems before a break up is inevitable.