Leah Remini knows Alex Rodriguez is the one for Jennifer Lopez.

The 'Second Act' co-stars have been close friends for almost 10 years, and the 48-year-old actress has revealed what it was that made her give the seal of approval for J-Lo's relationship with the former basketball player.

Speaking to E! News, she simply said: ''I think it's about seeing your friend happy, and that's when you know.''

Jennifer, 49, agreed with the sentiment, and said she has felt the same way seeing her pal with husband Angelo Pagán, who she married in 2003.

She added: ''You just want your bestie to be happy and fulfilled and in a good place and that's why I love seeing [Leah] with Angelo.

''You just know that that's their person. That's her ride or die. That's who makes her happy. That's who makes her thrive.''

While Jennifer has 10-year-old twins Max and Emme with her ex husband Marc Anthony, Leah and Angelo have 14-year-old daughter Sofia and the BFFs have loved seeing each other embrace family life.

J-Lo added: ''What we are most excited for and celebrate is our families. That is something that has grown over our friendship. I had babies after her but she was pregnant with Sofia when I met her so those big moments.''

Meanwhile, the star recently addressed wedding rumours, and admitted her fans want the ''fairy tale'' ending for her.

She said: ''Everyone wants a fairy tale. They all want a romantic comedy, a happy ending. We all do. But it's not a movie, even if you see us on Instagram or on the shows.''

And although the couple aren't engaged yet, they're taking their romance ''day-by-day'' and are enjoying every minute together.

She added: ''We're happy. We're taking it day-by-day. And it's great.''