Rihanna, Chris Brown vacation in Hawaii

Chris Brown and Rihanna vacation in Hawaii. (Splash Images, Instagram)

Rihanna turned 25 this week, and she celebrated by visiting one of this planet's most beautiful locations: tropical Hawaii. She strolled on the beach, sat by the ocean, and went jet-skiing to mark the occasional – and by her side, not so surprisingly, was Chris Brown.

Breakup rumours swirled around the controversial couple last week after they reportedly avoided each other at a nightclub and spent Valentine’s Day apart (Rihanna texting her ex Drake may or may not have had anything to do with the rift). But any spat between the two singers seems to be over, after they were seen cuddling and walking hand-in-hand on vacation. She also posted a photo of the pair in a limo on Instagram, with the caption “Pour it up pour it up! #birthdaybehavior,” as well as several other photos of them celebrating birthdays past.

See also: Rihanna's 10 most scandalous moments (PHOTOS)

Since this couple can barely sneeze without making headlines, the story of their reunion was soon public knowledge. And readers voiced their concerns immediately.

“Its like watching a car crash. You have a pretty good idea how it will end,” wrote a reader of an article on the U.K.’s Daily Mail website, which called Rihanna’s beach outfit “wildly inappropriate.”

Others wish to stay out of their business.

“*sigh* I don't understand why they can't just keep their relationship private. If they want to date, fine. But for the sake of their fans--and all of us who are just sick of this soap opera--how about keeping it to themselves?” wrote one reader on the Huffington Post.

See also: Rihanna bares it all in the tub for 'Stay' video

And some reminisce for the old days, just like RiRi’s old Instagram photos.

“RiRi and Chris Brown: remember when they were cute?” Kim Kardashian tweeted.

Rihanna's decision to reunite with the man who famously assaulted her has caused a variety of reactions -- ironically, some of them are even violent. At a nightclub in London on Feb. 17, one fan reportedly threw a bottle at Rihanna in anger.