Well, since House -- Mr. Curious about everything -- was the only one not questioning where she went, I think it was set up all along that he knew where she was.
I hope that's the case because I always thought it very strange that he appeared so disinterested about her disappearance - I remember hoping that it would be revealed that he knew what had happened.
Thanks all for the explanation on how Chase could have performed the wedding ceremony, I was boggled by that.
I'm really curious now to see how this marriage works out. That "oh shit, what have I done?" look on his face at the ceremony did not bode well.