"Angelina proposed to Brad recently and suggested a Christmas wedding. When Brad insisted they hold off, Angelina put him on a major guilt trip by telling him the kids want them to be married," a source told National Enquirer magazine.
"Brad thinks a wedding right now is biting off more than they can chew. He would like to slow down and go through some couples counselling. But Angelina is insisting they get married before they adopt again or have another biological baby," the source added.
Meanwhile, the 33-year-old actress is said to be undergoing fertility treatments in order to conceive a second set of biological twins with Brad, 45. "Angelina's doctors told her she has a strong chance of conceiving twins if she does it within two years after having her first pair. She has been seeing a fertility doctor regularly. She and Brad are monitoring when she is fertile. And they are trying really hard in the bedroom," a source said.