I know. I know. I know. Intellectually, I know it makes all kinds of sense for kids to go back and forth with parental preferences. I know that it also makes sense for Boy-o to gravitate to Mommy, one because she is super-fly cool, and he's not stuck with her all day every day, but two when I have been so constantly attuned and attached to his bambina sister for the past year and a bit.
But even with all that knowing, when your crying child shoves your attempts at comfort aside, yelling "No MAMA! I NEED MOMMY!", the old heart, it breaks a wee little bit.