Jennifer Lopez and Alex Rodriguez's children were a "driving force" in Alex's decision to propose.

Jennifer Lopez and Alex Rodriguez

Jennifer Lopez and Alex Rodriguez

The former baseball star popped the question to the 'Shades of Blue' actress over the weekend, and sources have now said his two children - Natasha, 14, and Ella, 10, whom he has with his ex-wife Cynthia Scurtis - as well as Jennifer's 11-year-old twins Max and Emme, whom she has with ex-husband Marc Anthony, were instrumental in the planning for the romantic moment.

A source said of their wedding plans: "The couple loves to entertain and have fun, and their wedding will be nothing short of incredible. Their kids will play a big part in their wedding, as they were a driving force in the proposal."

Insiders also say 49-year-old Jennifer was "shocked" by the proposal, as although they'd spoken about marriage before, she wasn't expecting the 43-year-old sportsman to pop the question that day.

The source added: "Jennifer was shocked as the two talked about marriage, but she wasn't aware he'd be proposing that day."

And although wedding preparations aren't underway just yet, the couple already know they want to invite their family and friends to watch them tie the knot when the big day arrives.

Speaking to 'Entertainment Tonight', the source said: "Both Alex and Jennifer have been married before, and official wedding planning hasn't started, but the two do want to celebrate the day with their family and famous friends."

Meanwhile, it was recently claimed Alex "did everything on his own" on the lead up to his proposal, including purchasing the mega-carat emerald-cut sparkler he presented Jennifer with.

An insider said: "He did everything on his own with the ring. It was a complete surprise [to Jen]."