Sounds like a lot of people using their foot or even their wife to hold the hose in. What happens in the evening when it's time for dinner or bed...what do you do with your foot?:R
"Executive" and a couple of others gave you the best advice. Not having some type of elbow on the hose, with a positive connection at the drain, is one of the biggest reasons for the hose to pop out.
You only really need a couple of pieces to meet every camping need. One is the stepped threaded connector and the rubber donut. Use a system where the hose elbow securely fits to stepped threaded connector and you're good to go. No threads on the drain, use the rubber donut.
We live out west and as messed up as California is, they aren't requiring all RV parks to have a positive connection and hose off of the ground as some states do, but you better be prepared for it if you're travelling to other states from your home state.