I have 6 sisters ... yes I definitely wore their clothes. Bras, panties, nightgowns, swimsuits, shorts, tops, skirts, dresses, jeans hose, garters, stockings, socks ...
3 of them knew then thanks to a game of truth or dare we were playing one night. They had me put on panties, bra and a swimsuit. After that it was a teasing joke between us ... 1 of them had suspected I was getting into their clothes and she nailed me when I didn't protest at the dare - I had put a run in a pair of her stockings and she found a pair of her panties and a bra in my room. She talked to me about it afterward and has been a confidant and supplier ever since.
Her only rule was and is wait for her to give them to me. She would round up all the clothes they couldn't wear at the end of the summer and after Christmas and give me first choice before it all went to goodwill or our cousins. She still does that now, brings me clothes throughout the year, things she doesn't wear anymore, things she ended up not liking etc.