There is no evidence to support the theory that this was a larger work when finished, and the bottom portion was removed for reasons of obscenity; the only clue is the man's expression, and that is an insufficient basis for conjecture.
It is obvious that the woman has a lover, and his name is Stanley. She she sees his name everywhere, so do we. But how does she get rid of her husband? She puts the Tanquery gin bottle in the cleaning closet, gets him accustomed to sneaking drinks in the dark from the familiar green bottle, then replaces the gin with a Stanleys product.
There will be police to deal with, of course. But she's dealt with them before.