The opposing side argues: That's too hasty! A special position can be for family or friends, it doesn't have to be a lover.
The opposing side retorts: Oh! Would you want your partner to have a special friend in their heart, who happens to like your partner and has even confessed?
Your partner might have rejected them, but still considers them a friend. Whenever they need help, your partner eagerly rushes over...
A couple of times might be fine, but after a while, are you sure your partner is still yours?
...
The friends were having a heated discussion, each with their own opinion on the matter.
Those who were more intense even said they hated partners like that. Back then, they had such a partner who had a special friend.
This friend was an admirer, confessed their feelings, and was rejected. Because of the rejection, they always felt a bit guilty, after all, the other person liked them so much.
Therefore, whenever this friend needed something, they would actively go to help.