Lyric discussion by Bluewaves 

Cover art for Suddenly Mary lyrics by Posies, The

I wonder what experience the "found my clothes inside the icebox" line came from.

Mary was incompetent at housework - the frozen dinners were in the washer?

Not Valid

I think that he is referring to an old trick where someone is skinny dipping and someone has hidden his clothes. As Michial said, it's in the context of a failing/failed marriage. I think the lyrics make an analogy of feeling trapped (hence the 'slavery' reference also in the song) and vulnerable in the marriage, the same as one would feel if they found that they didn't have clothes to put on and get away.