Welcome to Budapest (Clint Barton x OC Black Widow)

(Book 1 of the Hawk Widow series)
SHIELD agent Clint Barton is sent to kill the two most dangerous people the Black Widow's, but he can't do it, he can't kill them, so instead he recruits them into SHIELD, his boss Fury and handler Coulson and all the other SHIELD agents aren't too happy when the deadliest man on the planet walks in with the two deadliest women on the planet.

KGB, Red Room and HYDRA agents Natasha Romanoff and Samantha Romanoff are twins abandoned by their parents on the side of the road (or so they think) are sent to kill the man that has topped all three agencies hit-list's because Hawkeye is the only man on the planet who can go toe to toe with a Black Widow, survive and quite possibly survive, he has killed hundreds of Black Widow's and so they send the best of the best, but what happens when the girls make a pact to not shoot and allow him to kill them instead? But he can't do it, he can't kill them, so instead he recruits them into SHIELD, his boss Fury and handler Coulson and all the other SHIELD agents aren't too happy when the deadliest man on the planet walks in with the two deadliest women on the planet.