Douglas, spoke out about her true feelings for Reeve, who died in 2004 from a heart attack after years of being wheelchair-bound following a horse-riding accident in 1995 which left him paralyzed from the neck down.
The 55-year-old apparently admits she wasn't his biggest fan on the sets of Superman and Superman II, insisting he got wrapped up in playing the beloved role.
According to Britain's Daily Express, she said: "I've never really spoken about Christopher because he is no longer here to defend himself.
"But I used to be continually asked about him and, choosing my words carefully, would always say he's very much like Clark Kent: a real gent - very polite and perhaps a little dull.
"I never really knew him that well. I socialised with everybody else but not him. But at the beginning he was a very fresh-faced young American and at the end it was difficult. He definitely got caught up with his own Superman image."
Douglas said, "I suffered a lot of back injuries on Superman and could only walk for about an hour on the wires during my flying scenes and then had to have an hour off. And Christopher didn't take too kindly to the fact that this slowed things down so it was a bit tricky."
She also says actress Margot Kidder, who famously portrayed Lois Lane, also found Reeve hard to work alongside.
The actress claims that when she finally revealed her feelings to co-star Kidder, she replied: "Oh he was a right pain."
Douglas added: "I was so relived that somebody else had found him tricky. You don't want to speak ill of someone who has had a terrible accident. But my understanding is that after the injury everybody said he was a changed man and became an incredibly humble and generous guy."