Disrespectful or not ?

So my husband of 9 years has always had his high school girlfriend added on social media. She is also married with 3 kids. Well she is always the first to check out what he is posting, always comments on everything he posts & last night sent her a clip from the movie The Notebook, the scene where she says something along the lines of “it was real, we were kids but we were really in love”

He doesn’t think it’s disrespectful, I think it’s disrespectful not only towards me but towards her husband as well.

What do you guys think?