Mr Bennet often jokes about things and says things he doesn't mean.

For example when Mr Bennet says:
"I see no occasion for that. You and the girls may go, or you may send them by themselves, which perhaps will be still better, for as you are as handsome as any of them, Mr. Bingley might like you the best of the party." (chpt 1)
I doubt he really believes that there is a risk that Mr Bingley will really prefer Mrs Bennet to one of her daughters.

Another example is He had always intended to visit him, though to the last always assuring his wife that he should not go...