my favourite cousin figured it out at the family bbq and i dont know whether to deny or confide

cousin who im closest to in the family, we're same age basically, grew up together, properly tight. at the family bbq in bristol last weekend she pulled me aside and said "you and tom seem really happy these days, whatever you're doing, dont stop" with a look. then she said "and ive seen you tagged in some interesting places online" and just smiled. i went bright red. i think she knows. or at least suspects. part of me really wants to just be open with her, she's never been a judgemental person and ive missed sharing this side of myself. the other part of me is terrified itll leak to my aunt and then the whole extended family will know. has anyone confided in a sibling/cousin/close friend and not regretted it? mid thirties btw