YOU SAID:
i went over to my boyfriends house and pet his head
INTO JAPANESE
私は彼氏の家に行って、彼の頭をかわいがった
BACK INTO ENGLISH
I went to my boyfriend's house and loved his head.
INTO JAPANESE
私は彼氏の家に行き、彼の頭が大好きでした。
BACK INTO ENGLISH
I went to my boyfriend's house and loved his head.
That didn't even make that much sense in English.