User blog comment:Elizzzabear/Peter Hale is the Bride..... From Kill Bill, That Is./@comment-63.155.238.113-20121203072849/@comment-99.195.158.177-20130805004617

I believe I read somewhere that Jeff Davis made it canon that Peter did indeed know that Derek and Kate had a relationship. Considering his personality I wouldn't put it past him to spy on them anyway like he did with Derek and Paige.