The evidence that Rihanna and Drake may be in a serious relationship keeps piling on.

Last week, the two singers were photographed holding hands after leaving Tramps Nightclub, a club in London, together. In the picture, Rihanna's hand clutches Drake's as it lays upon his thigh. Check out the photo here.

According to sources, the buddng romance, which neither Take Care singer has admitted is official, is going successfully.

"It's working well," an Us Weekly source said.

According to Us Weekly "insiders," the feelings between the musicians are getting more and more intense.

"He lives for her, but she's really into him too," a source said.

Drake is reportedly winning over Rihanna's heart by being much different from her infamous ex, singer Chris Brown.

"Drake is really different from what she's used to," the source continued. "He's so different from the guys she usually likes ... they are really good together."

Rihanna was also recently spotted wearing an October's Very Own (OvO) jacket.

"[Rihanna] soon realized that Drake is the perfect gentleman -- the opposite of Chris," a Star magazine source "close to Rihanna" said. "[Drake] treats her like a queen."

Hollywood Life reports that Drake has bought Rihanna a $38,000 Cartier diamond watch and a $7,500 bracelet.

"Nothing is official in terms of their relationship, but they're still dating and sleeping with each other exclusively," a Hollywood Life insider explained. "You'll see them out and about, holding hands and being all lovey dovey these days. It's no secret that he belongs to her and she to him."

In his most recent interview with Rolling Stone, Drake said that he and Rihanna were just friends

"...but as far as them coming out and being like, 'Oh hey, look at us, it's official,' who knows when that's going to happen," the Hollywood Life source continued.

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Follow Scharon Harding on Twitter: @SH____4.