Martin took advantage of Piper's hard work at the restaurant, knowing that she would never stand up for herself. When he admitted this under effect of the Truth Spell, Piper finally quit. However, as the spell made everyone forget what had happened after it wore off, he forgot. When Martin later told her to get to work, Piper confronted him and finally stood up for herself and demanded he'd hire more personel.
Martin appeared in a total of 1 episode throughout the course of the series.