This holiday season could not get any merrier for Chris Brown as he is rumoured to be getting "serious" about Asian model Krista Santiago. While the rapper is showering his new love with exquisite gifts, it seems that his ex girlfriend Rihanna doubts his loyalty.

The Barbadian singer and Brown were in a long-term relationship until they got into a physical altercation in 2009. While the former lovers split ways after the incident, they have continued to maintain an amicable relationship.

"Rihanna's not really involved in Chris [Brown]'s life much, but to hear he's got a new girlfriend is cool and she's genuinely happy for him. It's the holidays and everyone deserves to be loved now more than ever," a source told Hollywood Life revealing that the Work singer, however, is wary of the 27-year-old's loyalty to his new girlfriend.

"She just hopes Chris does right by her, is faithful to her and loves her as he knows how," the source added.

"Chris was always a good lover," the source continued. "Being charming, sweet and surprising Rih with unexpected gifts and vacations was Chris' speciality. Rih misses that about him. But she's certain he's going to make this new girl of his very happy very fast".

Meanwhile, things seem to be heating up between the Loyal hitmaker and the Los Angeles-based model. After gifting Santiago an expensive Rolex watch on her birthday, Brown also introduced his new girlfriend to his 2-year-old daughter Royalty.

"She loves RoRo," claimed a report adding, "But the most serious gift he's given her is the key to his house! That's huge for him because he wants her to know that he's serious about her."

The With You singer was also dating American actress Karrueche Tran before being linked to his new girlfriend Santiago.