Taylor Swift played the role of supportive girlfriend yesterday ... accompanying her boyfriend Conor Kennedy as he visited his mother's grave site on Cape Cod.
The two were joined by several members of the Kennedy family, including Conor's brother and sister, who were all paying respects to the late Mary Richardson Kennedy.
Mary -- who married and divorced Robert F. Kennedy -- died back in May. Officials say the 52-year-old hanged herself in a barn. She had been suffering from serious bouts of addiction and depression for years.