Which reality TV show features a group of individuals living in a luxurious villa, engaging in social and romantic interactions, while periodically participating in challenges and eliminations, and often involves coupling up with other contestants?

1. Contestants often form strategic alliances to stay on the show.
2. The show typically features a narrator who provides witty commentary.
3. New participants regularly enter the villa to shake things up.
4. The show culminates with a public vote to determine the winning couple.