oldpunker,
That would freak me out. A big giant dildo. Women are strange though, who knows whats going on in her mind when she uses it. Maybe its not sexual at all but some kind of self actualizeing comfort thing. Dont be unjustly cruel to her or yourself. Maybe if you could determine how often she uses them. Perhaps its infrequent and only when shes stressed.
She may not even orgasm per say when using it.
You know -it may not- be a sexual thing but more of a PAIN thing, you know? Just because it involves a vagina and dildo does not mean that its what we men would consider a sexually centered type of mastraubation thing. It could be something totally different, some kind of psychological thing that has nothing to do with cocks, and lovers. Take it easy and check her out…you said she was cheated on? Maybe its some kinda of over compensation get back at my cheating husband trip perhaps. God life can be complicated.
I wish I had a grilfriend. Luck.
-copper