The 23-year-old raised eyebrows when she began dating Nick shortly after her mother's death in 2012, since Nick is known to have been taken in by Whitney and informally "adopted" by the legendary singer when he was younger.
But now that the couple are due to be married, Bobbi has hit back at critics who claim their relationship is incestuous and asserts that her late mum would have actually approved of their engagement.
Writing on her Facebook page this week, Bobbi said: "YES, we me nick are engaged. I'm tired of hearing people say "eww your engaged to your brother or if Whitney was still alive would we be together or would she approve of this." Let me clear up something, we aren't even real brother and sister nor is he my adoptive brother.
"My mum never adopted him. In fact, mommy was the one who even said that she knew that we were going to start dating. My mum knows me better than any of you. A lot of yall are saying that yall are only saying this all out of love. Which is bull because if that was so, all you would want is for me to be happy."
The aspiring actress also noted her frustration at other people "judging" her romance with Nick, especially as it makes her so happy.
"People need to seriously stop judging my relationship," she added. "Pretty sure it's my own decision who I want to be with. Yes, my relationship may not be perfect. We will have rough patches, just like every other relationship. And we have had our rough patches.
"You may or may not agree with my relationship. You may or may not respect it. Judge me, go ahead. Your opinions are yours and mine are mine. It is my life and not yours. The decisions I make have nothing to do with you. Goodnight."
Nick was thought to have proposed to Bobbi last year and she has since referred to him as her "fiancé" several times on Twitter.
The couple are now settling into a new home after recently moving out of their Atlanta apartment due their neighbours filing over ten noise complaints against them.
What do you think of Bobbi's public explanation of her relationship with Nick? Let us know below.
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Copyright: Instagram Mark Wright