Hi, Iano!
So what did you do? Did you repent earnestly in your morning prayers? Did you ask God why a Saint would have such evil thoughts in their mind?
Or were you really worried because the Lass in the dream was quite attractive and you feared the devil sneaking in the unconscious doorway?
From a psychological standpoint, dreams are thought to be ways in which our wiring gets condensed and rearranged more efficiently. There is also some theory about how dreams are unresolved issues in our waking conscious.
While im sure you would never commit adultery on a waking basis, perhaps the dream was a way for your soul to see what it would be like to give in to temptation. Perhaps a true attack of the devil, as it were.
Or maybe it is a test of your waking reaction.
What do you think?
“There are two kinds of people: those who say to God, "Thy will be done," and those to whom God says, "All right, then, have it your way” --C.S.Lewis