how can 2 people make the other 2 realize that they love each other?
The jealously game is the oldest trick in the book. Or you could get one of the protagonist defensive about the other when someone starts on insult them. If you're looking for something dramatic then maybe like a fake kidnapping or the (also) old in-the-hospital-dying-come-hither. Nothing like the prospect of never seeing someone again for the realization that you love someone 😆