Quoth the wiki;
Despite outward appearances, the reunion was an unhappy one for Stirm.
Three days before he arrived in the United States, the same day he was released from captivity, Stirm received a Dear John letter from his wife Loretta informing him that their marriage was over. Stirm later learned that Loretta had been with other men throughout his captivity, receiving marriage proposals from three of them.
In 1974, the Stirms divorced and Loretta remarried, but Lt Col Stirm was still ordered by the courts to provide her with 43% of his military retirement pay once he retired from the Air Force. Stirm was later promoted to full Colonel and retired from the Air Force in 1977.

Stirm was shot down over Hanoi on October 27, 1967.
Stirm was released from Vietnam on March 14, 1973.
The photo was taken at Travis AFB on March 17, 1973