When it comes to being in a serious relationship, there are all kinds of signs one can look for to determine if they’re with the right person or not, and one of the biggest ways to tell is if your significant other gets along with your friends.

Because there’s nothing worse than having to keep the person you love away from the friends that you love. It can be extremely tiring.

So there’s no doubt that Ashton Kutcher was pleased when his girlfriend Mila Kunis threw him a surprise birthday party over the weekend and secretly invited all of his friends. According to an inside source for Us Weekly, Kunis gets along superbly with Kutcher’s buddies.

“Mila gets along great with all of his friends,” said the insider. She’s like part of the crew.”

The former star of That ’70s Show turned 36 on Saturday night, so Kunis, who also played on the show, threw him a little shindig at La Poubelle restaurant, which is a regular hangout for Kutcher and his crew. The party only included close friends, and was more of an intimate gathering than a huge crazy blowout.

“It was very small,” revealed the insider. “Ashton has been going there for years and years. It’s one of his favorite spots, like home, so it was comfortable and they were well taken care of.”

Ever since Kutcher ended his marriage to actress Demi Moore, he’s been seen all over the place with Kunis, as it seemingly didn’t take much time for him to move on. And according to the Us Weekly source, Kunis has slowed him down a bit, to the point where he doesn’t really like to party much, which is why the surprise party was kept relatively small.

“They had been planning it for a while,” the source explained. “Ashton didn’t want a huge thing but they got a good group together. He’s certainly changed from how he used to like to party years ago. This was more of a wholesome situation. They had a great time.”

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