Jennifer Lopez: Marc Anthony “Started Crying” When He Found Out We Were Having Twins

 Kevin Mazur/WireImage.com

Jennifer Lopez still remembers what it was like when she found out she was expecting twins.

"Well, I was in denial that I was even pregnant at first, so when I found out I was having twins, I just kind of laughed like, 'Of course this would happen!'" The Back-Up Plan star, 40, said at a press conference for the movie in Beverly Hills Tuesday. "And then I started giggling."

How did hubby Marc Anthony react?

"Marc started crying," she recalls. "It was a joyous time. We were happy… He's emotional! He just couldn't believe it was happening. He'd had children before and this was like a whole new, special experience."

Now that Max and Emme are two years old, Lopez tells UsMagazine.com that they are starting to realize when she has to leave to work — and they don't like it.

"They're at the point now where they've come to the door and started yelling, 'No, no, Mommy, don't go!' And I was like, 'Whoa, this is bad,'" she tells Us. "That's really tough. So I'm just going to have to figure it out as I go along. I keep trying to explain to them, 'I'll be home and the sun will still be out!'"

Lopez, who plays a woman who decides to get artificially inseminated in her new flick, admits she wouldn't consider being a single mom in real life.

"It's just too hard!" Lopez says. "Honestly. I have so much respect for single moms or anyone who finds themselves a single mother — but to choose to be a single parent is courageous. It's such a hard job to raise a child and to be everything to that child without a partner… I don't know if I could do it on my own, I really don't."

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!