Reid was at nightclub Que Pasa in Camberley, Surrey, when a drag queen attempted to fondle Reid's genitals.
He was performing his new single 'Stardust' at the venue on Sunday (July 8).
"When I saw the pictures of Alex being groped by a drag queen in a Surrey nightclub the other weekend, I felt disgusted," she wrote in her New column.
"I'm also a bit hurt and I feel humiliated as well.
"It's in bad taste after all the stories that have been in the news about him. Alex and I have spoken about it, but that's all I want to say on the matter."
Houghton had briefly walked out on Reid back in May after she found him cross dressing in their home.
A source said: "Chantelle returned home to find Alex dressed as his alter ego Roxanne.
"He was indulging his fantasies and there were sex toys in the house. His eyes were 'wild and scary' and he looked strange. She'd never seen him like that before.
"She was so shocked and disgusted that she immediately returned to her old flat nearby. She was so desperate to get away from him that she had no choice but to sleep in an unfurnished flat."
However, the pair later reunited and they welcomed their first child together last month.
Watch the video for Alex Reid's 'Stardust' below: