I am not sure what do you mean with "their Pluto transiting my 8th house". I assume mean their natal Pluto is in your 7th house (provided you are talking about older people, this makes sense).
In this case, yes their Pluto is acting on your 7th house and may sometimes mean you suffer being manipulated or abused from other people (not necessarily sexual abuse).
I have understood in my case, abuse may concern Mars position too, not only Pluto or the 8th house. I had major sexual problems while Saturn aspected my Mars (square, conj and opposition mainly).
Also, look at the 8th house ruler position and aspects (the planet ruling the sign in which your 8th house cuspid is).