The Wedding Party by Jasmine Guillory
In the third installment in her Wedding Date series, Guillory links up Theo and Maddie, best friends of Alexa, who is set to be married in a few short months. After a disastrous first date, Maddie and Theo have avoided one another for months. But an encounter at a party has them seeing one another in a whole new light. They end up together that night and come to an agreement: they see one another in secret, but only until Alexa's wedding! Then they will end their masquerade with no hard feelings, and go about their lives.