I know exactly how you feel!!

Because we can totally trust Wiggles AND Jasper off leash, I know that for sure. I have NEVER even had to tell Jasper or anything, he naturally stays around(There has been people AND dogs walking right past our house, and Jasper just runs to the end of the lawn and makes a dead stop

Piddle, however , he always DECIDES that hes going to go for a walk by himself and he doesn't need to ask us or even let us know

Lately I have been letting him outside with the other 2, and I have been staying very close to him, and if he even made an attempt to go further than the lawn, or didn't come back when I called him to, he would go right in the house!

He has been listening alot better after a few weeks, I don't trust him completely(and may not ever) but I can still let him come out and play with the other 2 if Im there, as he doesnt attempt to go for his own little walk as much anymore