One Direction's Niall Horan made the fans crazy after he and rumored girlfriend Demi Lovato exchanged sweet tweets to each other.

Everyone is curios if the two are really going out as Niall Horan called Demi Lovato "honey" when the former greeted the latter on her birthday.The big question, "are they dating?" is still unanswered by the two.

The 18-year-old singer tweeted a special birthday message; "@ddlovato happy birthday honey! Have a lovely day. See ya soon."

"@NiallOfficial thank you sweet stuff! :)" Demi replied.

This caused chaos in the social networking site and "Nemi" couple was soon trending.

The heartthrob called Demi a "lovely girl" in one of his interviews. There were also rumors that the two communicate via Skype.

All of the rumors started when the singer said that he has a crush on Demi. When the singer was asked whether he and Demi are dating, the singer answered; "I wish! There's nothing going on, but she's a lovely girl."

The "X-Factor" judge said in one of her interviews that she has a "little" crush on the young singer. Last month, the former Disney wonder girl transformed into a new person when she rocked the purple carpet of this year's Teen Choice Awards by showing up in a futuristic and outrageous ensemble.

The 1D singer initially denied that there is something going on between him and Demi and said that they are good pals.

There are claims that Niall Horan probably wants some publicity for himself. The members of the popular boy band are involved in various controversies.

While Niall Horan is enjoying rumors of dating the former Disney sweetheart, co-member Harry Styles is suffering from news outbreak of cougar romance involving a lot of women older than him.

Currently, One Direction is taking a break from their commitments after completing their world tour.