Preggo!Olivia indeed! To everyone's surprise, not least her own :D

Stephen is discovering his need for privacy in general - it's part of the whole delayed growing-up arc he's going through. His feelings for Tad and Amy right now are a mess of confusion; it's just that his gut is telling him not to ask for Jon's help in sorting it out.

And yes, Stephen slipped back into his old usage of "sir." A symptom of the uncertainty he's going through in general.