I've tried a lot of things like onesies and boxer briefs to keep a heavy/wet diaper from sagging but here is a really great trick, control top pantyhose. In the winter at night I normally wear pantyhose over my diapers to keep my legs warm but I soon realized that it was doing a great job of keeping my diaper from sagging when wet. I know a lot of guys might have a problem wearing pantyhose, especially in the summer or in shorts so the answer is to simply cut off the legs just below the "panty". I normally use Leggs Sheer Energy, size Q+ (I'm 5'10", 220 lbs.), and when my winter time pantyhose get runs or holes I simply cut the legs off and presto, the perfect diaper support. I suspect that many of the women here already know how well this works but I bet many of the guys don't. By the way guys, you're already wearing a diaper so just one more unusual undergarment really isn't that big of a deal.