My Dearest Mr. Elche:
Dr. Putt would assume that you are writing because you are unwilling to pursue the obvious solution of terminating your partner's association with your foursome. She (Dr. Putt will not be sexist and assume that only men engage in such anti-social behavior, though he is certain that Mrs. Dr. Putt would disagree) or he must have some other highly admirable qualities that far outweigh these uncivilised distractions. Or perhaps you have some qualities that make selection of an alternative partner impossible?

Regardless, Dr. Putt would suggest a process of exposure and extinguishment. The next time you play, conceal a recording device on your person and record your partner's indiscretions. Take the recording home. Set up a three foot putt on the rug in your living room. Set up for the putt and then press the play button. Then sink the putt. Repeat the process: set up, play, sink the putt. Repeat over and over again until you are comfortable with your new routine, which we in the field of science might call "puttus interruptus." When you return to the battle of the green you will then be fully armed against these distractions; indeed, you will be using them to your advantage.

However, Dr. Putt must issue a warning of a possible side effect. You may not be able to putt with any success if your offensive partner is not present or if she/he ceases to engage in her/his usual behavior. As a backup, Dr. Putt would suggest you carry the recording device on your person and hit the play button as necessary. In the unlikely case that you should find this to be offensive to your playing partners, you might utilize a set of earphones. Maintaining proper etiquette is essential to the game.

Warmest regards,
Dr. Putt