WaT xover Vin is Martin
I thought I'd found the story I had in mind with Star-Crossed by Belladonna, but that's the wrong one. Same set up -- no, correction, Martin's not working undercover, he basically ran away from dad's influence and made himself over, living on the streets before joining Team Seven. Then Victor finds him and his threats against Chris make Martin decide to come back, then go work for Malone's team. It's either Christmas or Thanksgiving, Martin's at a party at Dad's and, feeling lonely and missing his brothers, he calls Chris's number. Even though he doesn't say anything, Chris figures out it's him. A little bit later Chris shows up at Martin's office and punches him for going away. Later or the next day Martin walks out of his apartment building to find his six brothers waiting for him. I can't remember if it's slash or not.