19-year-old James accused the "annoying" Coronation Street actress - who has clashed numerous times with his darts player father - of exaggerating her horror at the bushtucker trials in an attempt to win over the public.
"Helen is annoying and is clearly playing a game to get viewers onside," he told The Sun. "I don't think anyone was fooled by her over-dramatic reactions to the trials.
"The aim was clearly to pretend she couldn't deal with any of this stuff and then turn it around, winning people over. But I'd rather watch someone who is genuine - like my dad."
Flanagan has also been accused of playing a game by former I'm a Celebrity stars Mark Wright and Christopher Biggins, the latter jesting that he would have to "kill her and go and bury her in the jungle" if they were campmates.
However, Flanagan's parents have insisted that their daughter is not "a fake".
Bristow was saved from eviction this weekend after winning a head-to-head bushtucker trial against Doctor Who star Colin Baker.
The 55-year-old was also accused of "playing up to the cameras" by former campmate Limahl when he spoke to Digital Spy after his exit earlier this week.
I'm a Celebrity...Get Me Out of Here! continues tonight (November 26) at 8.30pm on ITV1.
Best ever bodies on I'm a Celebrity: