We presume this means that, at least for this couple, former President George H. W. Bush supports marriage equality:

Another prominent Republican has come out in support of same-sex marriage — or at least, in support of one particular same-sex marriage.

Former President George H.W. Bush served as an official witness this past weekend at the Maine wedding of Bonnie Clement and Helen Thorgalsen, co-owners of a Kennebunk general store. Thorgalsen posted a photo of the 41st commander-in-chief signing a set of documents for them at an outdoor celebration: “Getting our marriage license witnessed!”

Great picture:

ghwbwedding Former President George H. W. Bush Serves As Official Witness For Same Sex Marriage

(picture from the couple, Helen Thorgalsen and Bonnie Clement)