Engaging in sexual intercourse with two sisters OR daughter and mother, all within the same 24 hour period, but not at the same time. Easier to pull-off than a Trifecta, however still not an easy move to complete given the limited time frame and moral implications.
Ex. 1: Carl pulled a Daily Double yesterday when he hit it at lunch time for a nooner with Zoe, then went out with her sister Chloe for cocktails that evening and ended up spending the night with her.
Ex. 2: Raul noticed his date's mom flirting with him that evening, so the next day after a wild evening of sex with the daughter, he paid her mom a visit for some afternoon delight, thus scoring a Daily Double.