Simon Cowell reportedly dumped Lauren Silverman before he knew she was pregnant.
The 53-year-old music mogul is said to have ended his romance with the 36-year-old socialite - the wife of his close friend Andrew Silverman - six weeks ago, only to later discover she is expecting his baby.
He is said to have told a friend: "It's over with Lauren - it has been since before anyone knew she was pregnant. I want matters resolved but in a sensitive way. I have to respect a lot of people's feelings. There's a lot of people's feelings here."
Simon is said to be feeling "confused" about Lauren's pregnancy but has vowed to stand by her.
The source added to the Sunday Mirror newspaper: "Simon feels like he's been done up like a kipper in all of this."
"He and Lauren split up six weeks ago but the next thing we know he gets a phone call from her saying, 'Guess what?' Since then he has been feeling very confused about everything."
Another friend added: "He is excited about the baby and being a father and really will be as involved in the baby's life as he possibly can be.
"He'll support Lauren. But beyond that, everything else about the whole situation is very, very complicated and Simon is feeling in a real state and a bit down.
"The baby is great and exciting but it is the circumstances in which it has all happened. It's not the way he would have wanted it to happen.
"He doesn't know whether he has been set up or whether it is just one of those things."
Lauren's mother, Carole Saland, has slammed claims her daughter deliberately got pregnant to "trap" the 'X Factor' boss.
She told The Sun newspaper: "Lauren is not a gold-digger. She came from a very comfortable family and never lacked for anything.
"Her and Simon are very fond of each other. She tells me great things about him and has always spoken very highly of him.
"Lauren has told me Simon is so fun and nice and sweet.
"I trust Simon to do the right thing by my daughter."
Lauren - who is 10 weeks pregnant - has a seven-year-old son, Adam, with Andrew.
The casino boss has filed for divorce.