Spoilers here. This movie was mostly enjoyable. It's a rom-com which means we know the two main characters are going to get together at the end. So I'm not sure why others are complaining. I also personally see nothing wrong with two former lovers coming together after their children meet and get married.
But I thought that the marriage proposal at the end was way too soon- they'd only spent a few hours together on the island, and then had a huge misunderstanding, which means they don't really know or trust each other now as older adults. That's not a good basis for getting married. It would be nice if they took the time to learn who this person is now, before deciding to tie the knot. If she'd said "no, but ask me again in a year" to his proposal, and then they dated into the sunset, it would have felt like a more realistic ending. As it was, there was no build-up of their relationship that we could see.
But the location was gorgeous, the people all beautiful, so it was a pleasant watch.
Excellent acting by Brooke, Benjamin and pretty much everyone.