More agreeing with @Saintly_Loser than @ThelmaLou in the last couple of back-and-forths. So I’ll not rehash that but will pick at this one:
" ‘Take advantage of’ the girls" sure sounds paternalistic to me. As in they’re too innocent / stupid / unable to form ideas to be accountable for their own lives. So somebody else has to do it for them. Namely the clucking prudes who declared all sexual activity by young consenting women was an affront to nature and god. And indoctrinated a few generations of women with that nonsense from birth.
Thank goodness that too has mostly gone by the wayside of history.
As applied to folks of a fully sound mind. My earlier comments stand solidly in favor of protecting people not of sound mind. So I’ll answer your
… What constitutes “taking advantage of” in the context of the senior home?
that it’s about obtaining sex (or gifts, or money, or …) without willing consent knowingly given by someone competent to give it.
“Willing” is pretty easy to measure if you’re a third party witness. The devil lies in “knowing” and “competent”. And as always lies in the very gray middle, not at the white or black end of the spectrum.
If everyone on both sides is capable of consent and actually does consent, by definition it isn’t a predator.
There’s an old saying about women’s opportunities for finding a male mate in Alaska:
The odds are good but the goods are odd.
The point being that when / where women are in short supply they can “write their own ticket” and have their run of the willing men if they so choose. Again setting aside dementia, the elder living facilities are an example of the same odds, but favoring the male demographic.
Someone of either gender can “take advantage” of the demographic situation without “taking advantage” of any person in it. IOW “take advantage” has two meanings: “make legitimate use of a fortunate situation”, and “abusing”. One neutral, the other pejorative. We need to keep straight which flavor we’re each talking about.
IME.