There's probably a really good reason not to do it, but that's why I'm on here as I can't think of one myself or find one on google. In a couple of weeks I have to leave my 5 month ebf ds for the day with some expressed milk (and a sitter!) - I'm going to a no children wedding. Due to timings, location, plan of day etc, it would work out best to express in the car travelling there as well as at the venue later on. My husband, who will be driving, has a car with leather seats (wipe clean!), and I can pump straight into storage bags and have a small cool box. If I wear something to cover my wedding outfit, what could go wrong? Genuine question! Anyone done this themself?