I went to my aunt's house to hang out for the day.
Tips
usage
婶婶 specifically refers to the wife of your father's younger brother (叔叔). Chinese kinship terms are very precise — 伯母 (bómǔ) is the wife of father's older brother.
culture
婶婶 is also used as a polite way to address a woman of your parents' generation, even if unrelated, especially in northern China.