Decades after the events in question, Marina Oswald claimed that on the night of Thursday, November 21, 1963, her husband Lee Harvey Oswald suggested that they end their estrangement by having make-up sex (although I believe that term was unknown in 1963).
She claimed that while she was resigned to having sexual relations with Lee again, she wanted him to stew in his own juices one more day by making him wait for the weekend. However, she didn’t dangle a promise (or even a possibility) in front of him.
Marina claimed to be morally certain that this sexual rejection was what pushed “lone nut” Lee Harvey Oswald over the edge and made him impulsively bring his WWII-era Italian military rifle to work with him the next morning. Oswald’s life being a total mess (and finding no comfort on the home front), he decided to go out in a blaze of Marxist-Leninist glory.
That’s Marina’s story, and she’s sticking with it.