Good news: I found suitable summer trousers the other week in Marks and Spencer's. (I am not a dressy person. If it's not in Marks and Spencer's, I go without.)
Bad news: the trousers fasten with a zip and hooks and eyes; the hooks tend to unhook themselves after which the zip slowly unzips itself.
Good news: this doesn't matter that much because I always wear a long shirt (to cover my bottom) when I wear trousers so that the unfastened zip isn't really visible, and my stomach sticks out far enough so that the trousers don't descend round my ankles. Or at least not immediately.
Bad news: I bought two pairs of these trousers (the second for when the first wears out) and though I discover this design flaw immediately, I can't be bothered returning them to the shop. I just spend the day rehooking and rezipping.
Good news: this is tedious but not unbearably so.
Bad news: now a bit of material has got stuck in the zip so that it doesn't go down more than an inch.
Good news: this is enough for me to get the trousers off at necessary moments by pulling in my stomach.
More good news: then when the trousers are up again, I can let out my stomach and the trousers are fully secure.
Even better news: this is the first time I've discovered an advantage in having a stomach that sticks out. Read this and weep, Molly Bawn.