We are a couple in our early 40s and have visited We maspalomas and the famous dunes a few times. We have had some attention in the dunes before with men walking past and standing in some case's only a few meters away and staring at my wife. Some men move on quickly when you tell them we are not interested but we have had a few that have out stayed their welcome. 
We are happy to say hi but when men try and ask or hint for something sexual that can ruin a peaceful day on the beach quickly.