Mistletoe Match-Up (Romancing Wisconsin Series 3) by Stacey Joy Netzel

When Lisa Riley comes home for her brother Mark's Christmas Eve wedding, her high school rivalry with his wife Janelle's cousin, Derek Walsh, picks up right where it left off, only this time Derek has the upper hand. Santa bides his time as they battle it out because he's waited a whole year for this mistletoe match-up.