Apparently women sabotaging birth control isn't as uncommon as we'd like to believe. By now everyone's seen the 100+ page thread that says "42% of women would lie about birth control if they wished to become pregnant in spite of the wishes of their partner".
So now I ask you; - How would you react if you caught your partner poking holes in your condoms, or found out that she had never even purchased birth control pills despite telling you that she's currently taking them?