When you are born you get your soulmates first words they say to you written on your wrist with a symbol and Natasha's were "that's not important what's important is that I'm here to kill you" and Clint's were "who are you".

Clint was on a mission to kill the black widow and he has been following her for a few days and one day she is in an alleyway and he drops down from the roof. "who are you" Natasha asks backing away "that's not important what is important is that I'm here to kill you" Clint responds "than do it" Natasha tells him and he looks into her eyes and sees that she is not afraid of dying but afraid of another thing.

"let's make a deal" Clint tells her "what" Natasha asks shocked "I don't kill you and you come work at SHIELD with me" Clint offers her the same thing Phil had offered him "ok" she agrees and he helps her up and her sleeve falls down and he looks at her tattoo and than his and she does the same.

"well what does this mean" Natasha asks as the mark turns silver "I guess we're soulmates" Clint shrugs "I always wondered who would say that to their soulmate" Natasha says with a teasing smile.