We see a pretty 17 year old seduce her lonely balding teacher, we're unlikely to view this situation in the same way, more like the alternate case, the lady and the younger man. The victim isn't much of a victim, and the perpetrator is viewed as weak and untrustworthy, as opposed to a vicious sexual predator. By and large though, except maybe for a lesbian interaction or a very young male, say 14 or less, there will not be too many cases where we'd tend to assume the woman in question was a vile criminal, but the emphasis always has to be 'not too many' as opposed to 'none', and vice versa, there will be cases where even though the people involved are apparently attractive older woman and normal teenage boy, some serious victimization took place, and also of course, that the victimization can go back the other way, the younger person abusing the older one, though obviously in such a case the older person is likely to need to be removed form a position of authority regardless. So long as we look at it that way, I don't think we need to worry too much that we're practicing unfair double standards.