THIS LIST WILL HAVE SPOILERS!!!! The other romantic lead is so awful that you have no choice but to choose the main romantic lead the author clearly wants you to choose. It comes across as a convenient shortcut, avoiding the complex choice the protagonist could have faced and stripping the story of greater depth. The second romantic lead doesn't have to be that bad, or done something so unforgivable for readers to justify their elimination or why MC chooses the main romantic lead.