Bren, 78, paid child support for his two children, but those children said that the child support wasn't enough, and they deserve more.
Bren fathered Christie Bren, 22, and David Bren,18, in the late 1980s and claimed he paid more than $10 million in child support to their mother, Jennifer Gold.
The lawsuit alleges that Bren actually paid far less, somewhere in the amount of $3 million. The lawsuit also alleges that Bren made false promises to Gold about being involved in the children's lives.
Bren took the stand at the Los Angeles Superior Court Wednesday and said that he never loved the children's mother, but financially supported his kids. Now the jury has to decide if that support was enough.
"To sit in a courtroom, face his children and say 'I don't love your mother, and frankly, I didn't really want to have you,' that's the tension that's created in that courtroom," said defense attorney Dana Cole.
Former prosecutor Robin Sax said the question of greed will come into play.
"The key to this case is that there was a prior agreement that was held up to be a valid agreement, so you would think because that agreement was entered into by the mother of these children and that that would remain valid. So the question of greed really seems apparent because now they're coming back after the fact, after they're adults, wanting more cash," said Sax.
According to published reports, all of the legal issues started about a decade ago during a chance meeting between Bren and his children at a restaurant when he brushed them off.
Bren is a real estate mogul and is the chairman of the Irvine Co. He has been married several times and has other children. Bren is 16th on the Forbes wealth list, with an estimated worth of $12 billion.