I could find only one website, Frank Lennon's Midi Music Classroom, which has the above song, so I assume the lyrics were copied from there. The website owner, if I understand him correctly, seems to be claiming it as his original composition. Anyway, he cites no source, and I can't find any other reference to it, or evidence that it was ever recorded. Frankly, I'm surprised anyone requested it, and anyone found it!

While searching for the origin of the above song, I found the one below—not the one requested, apparently, and not appropriate for a wedding, but widely recorded, and found at many places on the Internet (Google gets 250+ hits):

TAKE GOOD CARE OF HER
Arthur Kent & Edward C. Warren, © 1961 Summit Music

Take good care of her. Take good care of her.
I suppose I ought to say congratulations
For you won the only girl I ever loved,
But I hurt too much to face the situation.
Just take good care of her. Take good care of her.

Just to be around her was my greatest pleasure.
She was everything my future held in store.
So remember when you take my only treasure,
Just take good care of her. Take good care of her.

I must accept it. She loves you more than me.
So with my broken heart I'll bow out gracefully.
Please don't send me any wedding invitation,
For I couldn't bear to see her there with you.
If she's happy, that will be my consolation.
Just take good care of her. Take good care of her.

Take good care of her. Take good care of her.

[Recorded by Elvis Presley, Roy Drusky, Ferlin Husky, Sonny James, Dean Martin, Daniel O'Donnell, Cliff Richard, The Statler Brothers, The Wilburn Brothers, and several others.]