Houghton revealed that she is now "suspicious" of men, and said that it will be difficult for another man to gain her trust.
Writing in her Now magazine column, Houghton said: "I'm suspicious now. It'll take a lot for me to believe in someone and it'll take time.
"I don't want some guy around me who's going to be bad. Whoever I do date will have nothing to do with Alex. My number one concern is Dolly, so anyone that does come into my life would have to be pretty special."
The 29-year-old reality TV star has 6-month-old daughter Dolly with cage fighter Reid.
Houghton and Reid got together in August 2011, with Reid proposing to her in October that year live on Ireland's Saturday Night Show TV series.