Complex sentence: The vampire takes the opportunity to emphasize his having Buffy with him, but Riley does care yet pretends to not care; he identifies Spike as "The Doctor" and demands to know where the eggs are.
Split into simpler sentences: The vampire takes the opportunity to emphasize his having Buffy with him. Riley pretends not to care although he clearly does; he identifies Spike as "The Doctor" and demands to know where the eggs are.