Here's a little relationship timeline for you:
July 3, 1965: John McCain marries Carol Shepp.
Mid-70's: John has several extramarital affairs
April 1979: John, still married to Carol, meets Cindy Hensley in Hawaii
April 1979-??: John and Cindy travel between Arizona and Washington DC to continue their relationship.
January 7, 1980: John McCain last "cohabitation" with Carol McCain
February 19, 1980: John first sues Carol for divorce.
March 6, 1980: John Applies for Marriage License.
April 2, 1980: John and Carol's Divorce finalized.
May 17, 1980: John and Cindy get married.
Imagine the "family values" uproar if John were a Democrat....