Complex sentence: On their way out, they encounter Billy Christensen, who is now Christie's husband: he is now an overweight alcoholic, living a miserable life with Christie, and unsure if he's the father of her latest pregnancy.
Split into simpler sentences: On their way out, they encounter Billy Christensen, who is now Christie's husband. He's a pot-bellied alcoholic, living a miserable life with Christie, unsure if he's even fathered her latest pregnancy.