In "Transitions", Blossom is worried that Six has a drinking problem. Her boyfriend Vinnie tells her that she should mind her own business and that if Six is going to drag herself down, she just has to let her do it. At first, the advice seems very insensitive but then I remembered that an earlier episode strongly hinted that Vinnie's father was an alcoholic (he sneaks in to Blossom's house in the middle of the night saying that his dad "came home loaded again"). He was probably just speaking from personal experience. If he couldn't get his father to stop drinking, why should he expect Blossom to succeed in doing it with Six?
I always thought it was weird that a hunky star athlete like Joey couldn't get laid for most of the show's run? Was it just a case of All Women Are Prudes? Then I realized that all the women he went for were conventionally "hot babes." If he had lowered his standards a bit, he probably would have had a much easier time.