Is it weird to borrow underwear from family/friends?

Recently I was driving home from a long day of meetings down south, i was very tired and my sister said I was welcome to stay at hers as its about halfway back home and on the way. I slept in the spare room and next morning after we finished breakfast I said to my sister " please can I borrow some clean knickers I haven't for any spares as because I thought I would be driving home last night. She said of course. Her husband then thought it was a strange thing to do and even said wouldn't you rather wear a dirty pair? I would'nt lend my underwear to my brother laughing. Kate my sister laughed and said girls often do it. After I showered me and my sister were in her room getting dressed. I got out some knickers from her drawer just some nude bikinis and put them on. Well her hubby comes in and couldn't believe we were being serious. Laughed about it being strange seeing someone else in his wife's underwear.

Surely im not the only one who is happy to borrow or lend undies?