This is a Swati culture called (Kutekwa) a man will invite his gf to visit him ekhaya kubo and not tell her what's going to happen in the morning, also he will not lock the door, around 3am-4am, his sisters will knock and say "vuka makoti sikutekile"
They'll take her and dress her isidwaba, also give her umkhoto then take her to the kraal, she'll cry there (some don't cry) his sisters nabo anti will sing (as seen in the video) until the sun comes out, the kraal is a very sacred place, entering there is letting the elders know that the son is taking a wife.
**This is just a short version of it, its a long process