Orin isn't close with any of his cousins, and most of them weren't in his age group anyway. Orin does, however, have a half brother through his dad who he's around 12 years older than...
After the split, both of Orin's parents began seeing other people, though Orin's mom never had another child. However, his father, Al, did end up having a son with a British student named Lily who had been sent to America by her family. She was only 19 when she got together with Orin's dad who was in his 40s, and she gave birth to Orin's little brother Kevin shortly after.
Orin was living with his mother at the time but would visit his dad occasionally and thus would visit his...not quite step-mom. Orin didn't have warm feelings toward his father, but he was fond of Lily who he viewed more like a sister than an adult figure. And of course that also meant meeting and spending time with his new, baby, brother Kevin. He almost immediately became very attached to his little brother and Lily, even feeling protective and defensive of them...especially since he knew what living with his father was like.
By the time Orin's mother died and he was forced to live with his father, Lily had moved out and taken Kevin with her, but she still lived locally, and when he didn't want to be at home with his dad he would go visit Lily and would babysit Kevin who was a toddler now, being something of a good but mostly questionable influence on his rambunctious little sibling. The little trio remained close, and when Orin eventually escaped from his father at 18, he immediately went to Lily's place when he needed a place to stay before going away to school. She didn't ask any questions about what happened with his father, and she was grateful to have an extra set of hands to wrangle Kevin who was turning into quite the troublemaker...a trait that seems to run in the family...
While he was away at school he'd get letters from Lily telling him about how life was going and updating him on Kevin, sending him pictures, and he'd always write her back. This only strengthened his feelings of closeness and family with her. He spent his summer and winter break with Lily and Kevin, but that only lasted for two years...
He was still in school when Lily made the decision to move back home to England to be with her family. The war had ended, and her sister had had a child of her own, a little boy named Tommy who she wanted to meet and who was proving to be a bit of a difficult child, though her sister hadn't specified exactly how. And well, truthfully, she was homesick and wanted to raise her son around his cousin and her sister...as you can imagine, Orin didn't take this news very well.
He felt like he was being abandoned by her, his only close family, and he grew cold toward her almost immediately. His feelings toward Kevin were much softer since he was just a kid, but his feelings of betrayal colored his over all feelings toward the both of them. Even after she moved, Lily would still send Orin letters and Christmas cards, but Orin didn't write back nearly as often. He did visit England once when Kevin was 15 and reconnected with him while he was there, but he kept his distance from Lily who he still held a grudge against for "leaving".
Kevin looked up to Orin who he was closer with than his actual dad and who he felt comfortable enough around to complain about the "total bore" of a step-dad Lily had married since moving back to England. Did Orin give his little brother cigarettes? Maybe. But he was also a listening ear and genuinely cared and cares about his little brother's well-being and did stay in touch with him.
So he's got a sort of sister he's not actually related to who is the mother of his actual half-brother who he's significantly older than. And their level of closeness depends on where in Orin's life you're asking...
