Falling in Love Again (Sweet Dreams #23)
Barbara Conklin

She hadn't counted on the school play, though. Somehow her crazy friend Amy ropes her into working on the props. Before she knows it, Mariah's the understudy for the female lead! And she can't help but notice Dan Gordon, the male lead.
When Dan asks her out, Mariah doesn't know what to think. He's sweet and funny and understanding - but she can't forget Paul. His memory seems to always be between them.
Then D and tires of being second best, and Mariah knows she must choose - between Dan who loves her now, and Paul who loved her first...