Worry and distrust
After Stitch rejected her proposal for having another baby, Abby distanced herself from the marriage and realized that perhaps she wasn't ready to try again. But, as soon as she had made peace with her decision, Stitch surprised her and said he now wanted to make another effort at expanding their family.
While Abby played along at first, she ultimately cracked and revealed that she had been taking birth control and wasn't ready to get pregnant. The confession crushed Stitch, who couldn't believe his wife would keep her true feelings from him.