Fans are loving the fact that Jennifer Lopez and Alex Rodriguez are dating — but In Touch can exclusively reveal that the MLB star has some ground rules for their relationship.

Sources explain that Alex took issue with the fact that J.Lo kept in contact with her ex-boyfriend Casper Smart and had her cut off communication.

“[He] made it very clear that he isn’t comfortable with them talking and that it needs to stop,” says an insider, who adds the Shades of Blue actress feels the same way.

jennifer lopez casper smart getty images

"She usually doesn’t listen to a man telling her what to do, but she likes that Alex is expressing how he feels and is a little bit jealous."

Jennifer recently revealed how the hot new couple met on an episode of The Ellen DeGeneres Show.

MORE: Jennifer Lopez and Alex Rodriguez Hit the Dance Floor on Vacation — See the Video

"I was having lunch somewhere and I saw him and he passed by. Afterward, I went outside. For some reason, I just felt like tapping him on the shoulder and saying hi," she explained.

In Touch previously reported that the couple is so in love that they're already talking marriage!

“She really wants to marry Alex by the end of the year. She doesn’t want to wait because she knows he’s her soul mate,” a source revealed earlier this month, adding they've even talked about a prenuptial agreement.

“Jennifer not only wants to protect her money, she wants to make sure her kids [nine-year-old twins Max and Emme] are taken care of," the insider explained. “Alex is always on top of his finances, so a prenup is very important to him, too.”

MORE: Enter Here for Your Chance to Win $1 Million

Alex also has two children from a previous relationship — daughters Natasha, 12, and Ella, 9.

For more on this, pick up the latest issue of In Touch — and for more exclusive content sign up for our newsletter!