Shout to my ex

In the music video 'Shout Out To My Ex' by Little Mix, you can clearly see that the four girls are objectified mainly by their revealing outfits they have got on throughout the whole video. In total throughout the entirety of the video they were three different outfits, all of these are revealing and sexualise them either by accentuating their curves or just generally being short and revealing. For example one of the scenes they are all round a swimming pool in their bikinis etc, which is obviously very relatable and its understandable why they have revealing clothes on. But my question is, what does swimming have to do with your ex? The primary aim throughout the whole music video is to make them attractive, which doesn't make any sense when their target audience is mainly young girls.