Summertree

Summertree is a 1971 film directed by Anthony Newley. The screenplay was written by Edward Hume and Stephen Yafa, based on the 1967 play of the same name by Ron Cowen.

Inspired by a television advertisement, Jerry becomes a Big Brother to a black child named Marvis. When Jerry is slightly injured in a fall, they visit a hospital where Jerry meets a nurse named Vanetta Brenda Vaccaro. They soon fall in love despite Vanetta being older than Jerry and begin living with each other.Jerry accidentally discovers an autographed photo of Vanetta declaring her love to a man named Tony Bill Vint. Vanetta explains that Tony is her husband and they separated two years ago but are not divorced. Tony pops in for a visit wearing his Marine uniform with Vietnam decorations. Tony tells Jerry that Vanetta promised to wait for him with Jerry leaving for Vanetta and Tony to clear their personal issues. ........

Source: Wikipedia