Karrueche Tran Cheated [Again]? Chris Brown 'Likes' Sexy Rihanna Bikini PHOTO On Instagram, 'X' Rapper Wants Threesome Relationship?

Karrueche Tran's relationship with Chris Brown is going great (for now):

But if Breezy's so "smitten" with his 26-year-old model sweetheart, why can't he keep ex-girlfriend Rihanna off of his mind?

Chrianna broke-up awhile ago, but the "Loyal" crooner still considers RiRi a very talented artist - and a "close friend." In a recent interview with Access Hollywood, the rapper reveals:

"I think people kinda always get misconceptions because if you don't see [Rihanna and I] in the headlines dating or with each other, it's always, 'Oh, they hate each other.' Me and her are friends. We have a great understanding. There's no issues... At the end of the day, we'll do music. If the time is right, if she's working on an album and wants me on a record, she can call, I'll get on the record. If I need her on something, and vice versa... that friendship speaks volumes. We've been friends, we've known each other for almost 10 years, the same amount of time I've been doing music. I don't think that's ever gonna change. It is what it is - we're friends."

And earlier this month, Brown flaunted an angel chain while performing on "The Tonight Show With Jimmy Fallon" (RiRi owns a very similar piece of jewelry):

Plus - just over the summer, the X superstar allegedly "liked" a viral Instagram photo of the "Pour It Up" beauty flaunting a racy bikini.

Now he's done it again.

According to the infamous gossip webloid ThyBlackMan.com, Breezy recognized two snapshots on the popular social networking site on Tuesday (Sept. 23). One image featured his ex-lover posing in another skimpy bikini:

Some fans were angry with the R&B heartthrob for "flirting" behind Tran's back, so the "like" was mysteriously deleted.

But according to an insider from MTV, Breezy still only has eyes for the aspiring fashionista, and he wants to settle down soon:

"All he wants is to be peaceful and to set up shop somewhere that will make him and Karrueche Tran happy... That's his lady. He wouldn't have it any other way. He loves her, loves being with her and one of the things he promised her while he was in jail was that he would stick by her, and he's continuing to do that."

But do Mstars readers think Brown's feelings for RiRi will ever fizzle-out for good?