Ex grabbed/hugged her waist for a quick moment. Is this suspicious behavior?

Asking for a friend.

Her and her ex were each other's first love and first relationship. They met in middle school, and were best friends all throughout it and got together in high school. They use to be very touchy and would be very physically close like they'd play fight a lot when they were friends before getting together. After their breakup they always kept very loosely in touch throughout the years. It wasn't until 3 years ago that they really reconnected thanks to some mutual friends and hung out but since it's only been every once in a while until a few months ago they started seeing each other more often.

A few days ago they hung out with a mutual friend (another guy) and amongst the 3 were recording a video just goofing off when her ex suddenly came from behind playfully and hugged/grabbed her waist for a moment. Her other guy friend has never been like that with her and her ex hasn't been that intimate with her since they were together (more than 10 years ago). Since their reconnection, her and her ex have hugged platonically but that's it.

Extra detail: he's not the kind of guy to be friends with his exes and likes to leave that in the past for good, but it looks like the only ex he's friends with is my friend..

Thoughts?

Ex grabbed/hugged her waist for a quick moment. Is this suspicious behavior?
Post Opinion