[BL] Due to a rare condition, Vince’s end of the red string of fate is tied around his neck, while his soulmate's, Jack, is tied around his finger, like it’s supposed to be.

Theory says that if they "sleep" with someone that isn’t their soulmate, the string tightens on the other end, letting your soulmate know exactly what you are doing.
When Jack feels his string tightening, he feels heartbroken, and starts to sleep around with everybody as revenge, not knowing Vince was a victim of abuse.

When they finally meet, Vince is already suffocating.

or -
Love and fate's hopes for humanity were way too high and all they got was disappointment

Singularity: The Red String Around Your Neck

Theo watches Vince’s eyes fill with tears. 


“I can't.” Vince swallows down a sob. “I'm just starting to live normally again, having dreams and plans for the future and I... I don't wanna get hurt." 


"Why are you so sure he's gonna hurt you?" 


"He did it before, didn't he?" He smiles bitterly. "And I don't wanna ruin what we just started to build. He- He seems to be happy with being just friends. And I should... No, I am happy too." 


Theo closes his eyes, breathing in as he hopes he'll find the right words to say. 


Chapter XXXV