Tammy LaFontaine is the daughter of Ronnie and Amber LaFontaine, the Dunphy's next-door neighbors.
Luke developed a crush on Tammy, watching her sunbathe on her parents boat, from his bedroom window. Luke tried to talk to her, while she blew him off and insulted him. Alex gave him advice to just ignore Tammy when they saw each other, which he did — which in turn bothered Tammy enough that she wanted him to come back and talk to her.