If this had been set in the U.S. rather than Britain...
Joe would have been at the very least fired from his coaching job (especially if he was coaching high school sports), and possibly even arrested, for carrying on a romantic relationship with one (almost two) of his players.
If you are a male coaching high-school age female players (male too for that matter) in any sport, that is one of the absolute first things you learn -- you cannot carry on any sort of romantic or sexual pursuit of your players, at all -- you cannot even allow any hint of suggestion it might be going on.
Therefore if he was taking his team to any tournament out of state or something (like the German tournament in BILB) he would have to bring along a couple of player mothers to act as chaperones. He would simply not be allowed to take players out to a nightclub.
Of course high school age girls would not be allowed in an alcohol nightclub anyway.
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4) You ever seen Superman $#$# his pants? Case closed.