The so-called "adopted son" of Whitney Houston is denying reports that he and the late singer's daughter Bobbi Kristina are an item.

"We're just close -- just going through her mom's passing and grieving together," Nick Gordon told ABCNews.com. 

News reports and Twitter feeds have fueled speculation that the two are dating.

Bobbi Kristina and Gordon were seen kissing and holding hands in a Target store in Georgia last week, according to HollywoodLife.

Houston reportedly invited Gordon, now 22, into her home more than 10 years ago and helped raise him, but didn't legally adopt him.  

Although 19-year-old Bobbi Kristina and Gordon refer to each other as siblings -- "brudder" and "lil sis" -- Gordon made it clear last night that they're not related, tweeting about Houston, "For the stupid ppl out there she gave birth to 1 child. And she trusted me with EVERYTHING!" He added, "She called me her "God Son" I swear some ppl in this world act like they don't have a brain..."  

On Monday, Gordon tweeted: "Yea we got a little closer and what?" He addressed "all the haters" by saying, "Some ppl have no lives so they gotta be in ours." 

Bobbi Kristina retweeted one of Gordon's tweets, along with some positive feedback from supporters.