In Act 3, Scene 2, why does Macbeth not tell Lady Macbeth about his plans to murder Banquo?

Macbeth says to Lady Macbeth, "Be innocent of the knowledge, dearest chuck, / Till thou applaud the deed."  He is telling her that he doesn't want her to know until after the deed and then she'll be pleased with what he's done.   There are a couple possible reasons for why he isn't telling her.  It could be that he wants her to be proud of him for having the ability to plan and carry out a murder on his own.  In Act 1, sc. 7, when Macbeth suggests to his wife that they not go through with the murder of Duncan, she essentially calls him a wimp.  She attacks his masculinity and her tactic worked because Macbeth decides to go along with her.  She is the one who devised the plan, too. So it is entirely possible that he is trying to impress her.  Another possible reason for not telling Lady Macbeth of his plan to have Banquo and Fleance killed is "plausible deniability", but I have more belief in the first reason.