I try to leave my dogs together for as long as they can stay that way. Sometimes it is several months and every now and then it is only a matter of weeks. Always different.

My buddy had a female, Ch. Angel, who would run and play with his Heelers all thru the woods. She wrestled and play fought like she did not have a care in the world. Personally I was always waiting for the horrible accident but it never happened. Close a door and step over a wall and she would go absolutely bat shit crazy, a highly intense methodical killer.
Step over the wall, walk out in the yard and she was Scooby Doo all over again.

I had one that could do that til he was about 14-15 months old and then one day he decided no more play time for him. Four legs? Check. Fur? Check. Go berserk? Check that box too.

It is possible to allow them to be together and in some cases it may last a life time. I just think it is flirting with disaster. But to each his own. EWO