The soap hunk thanked his partner while collecting the 'Most Popular Newcomer' award for his portrayal of Joey Branning, prompting jealous jeers from those gathered in the O2 Arena.
David Witts with his girlfriend after learning of his 'Most Popular Newcomer' award
Clearly stunned by the crowd's response, Witts broke off his acceptance speech to tell them: "Don't boo! That's rude. You can't boo her, she is beautiful, look at her. She is far too good for me."
David Witts reacts to the boos for his girlfriend
Some Twitter users had even more extreme reactions to the news that Witts has a girlfriend, with one warning her: "I will find u and kidnap u."
However, most on the site were shocked by the negativity of the crowd, calling those who booed "psychopaths", "vile" and "tragic".
Speaking to Digital Spy following his win, Witts revealed that his girlfriend had helped him prepare the speech in which she was booed.
"I didn't expect to win. I really didn't," he said. "On my way here with my girlfriend, she said, 'You really should make a list of some people to thank', and I was like, 'Oh, really?'"
Witts previously admitted that his partner is not comfortable with his sex symbol status.
"She has got used to the on-screen kissing. She understands it is a job. But the attention outside the show is different," he explained.
"You have to accept that with this job, some kind of hype does come with it. As long as you don't believe the hype and carry on as normal then you are fine."
Witts beat Emmerdale's Liam Fox, Coronation Street's Natalie Gumede and Hollyoaks actor Joseph Thompson to the 'Most Popular Newcomer' award, which was voted for by the public.
National Television Awards 2013: Winners: