Longer term bondage can have some issues. One in particular is what to do when your bound boy has to urinate. Do you untie him, release him, or have him take care of it himself? I prefer to put boys into diapers for longer term bondage. It is convenient as it allows them to urinate whenever they need to. It also helps put them into more of a submissive mode when they realize they will be wetting their own diaper. Being bound and laying in your own urine can be quite humiliating for some boys. Others enjoy it. Either way, it takes care of one difficulty of longer term bondage. Diapering a boy can be a lot of fun too. I do recommend using Abena M3 or M4 diapers, as they can hold quite a bit. To reduce the chance of a spill, plastic pants over the diapers and putting the boy into chastity are two good options. The chastity device points the boys cock downwards which helps to prevent any urine from coming out the top of the diaper.
Sparky in a Sleepsack
My pup loves spending time in sleepsacks. His favorite seems to be our Mr S Neoprene Sleepsack. I think it is because it can be tightened with rope, making for a nice snug fit.