hows this?
I found a picture of both the glass and the wedding couple.
pasted them both in different layers. (wedding picture on top layer)
Cropped the wedding photo to the size of the water in the glass.
Played with the opacity of the first layer, to make it seem as the picture was blended with the water.
Feathered the wedding photo to get rid of the rough edges.
and the played around with the brightness of the wedding photo.
flatten, and its done.