Well I suppose Sean could be shocked about Stacey deciding to keep the baby (if she does).
It sounds like Sean might be against her settling down at her age.
But then again if she has a miscarriage it would explain all the emotional scenes. If Stacey just decided to keep the baby, there'd be more rows, than Stacey crying in Bradley's arms. With a miscarriage they could make the crying and talking go on forever!