I urge you to talk properly to your wife put all the cards on the table as you love your wife but her actions are making you un'eased.
Please talk it out with your wife and put an end to this.
Don't assume nudity equals sex, as you eill often be wrong.
In that context, was is not sexual, and not an attempt to seduce or any of the other things suggested in some answers.
There was never any sex or improper intent.
Its a psychoanalytic theory based on the work of Sigmund Freud, which is a complex of females; it deals with sexual attraction to the father.