The 'Love Story' hitmaker, who began dating the 18-year-old son of Robert Kennedy Jr in June, wanted to show her parents how serious she is in her new relation, reported Contactmusic.
While they were there, the pair enjoyed a date at a barbecue diner and onlookers say they couldn't keep their hands off each other.
Swift, 22, has previously dated John Mayer, Joe Jonas and Jake Gyllenhaal.