"You don't make me laugh anymore" has been my wife's SINGLE BIGGEST COMPLAINT each of the last three confrontations we've had over the past several years!!!
But it's a damned-near-impossible chicken-and-egg, as CeMar points out. She doesn't want to be intimate with you, because you're grouchy and humorless; you're grouchy and humorless because she never wants to be intimate with you.
Personally, if my very future -- and my kids' future -- weren't at stake here, I don't think I could pull of the happy, humorous moments I've managed to drum up the past week, and even then, I'm only succeeding half the time.