Well, the mystery is finally solved. I did my research. Paternity Riddle No. 2 tells the tale
The riddle reads:
Grumpy has at least 8 great-great-grandchildren, 5 of which are on the 2011 name list." Who's the grandchild linking Grumpy to them - and who may have been the parent?
When Evi gave the answer she said:
"Stinky VMMM012 was indeed Young's father!
Born on 20th January 2004 he was part of Grumpy's first litter which also included his brothers The Groke (VMMM011), Too-Ticky (VMMM013) and sister Hemulen (VMMF010). He started roving in the middle of what must be meerkat puberty, at the tender age of nine months. He and his brother The Groke were the sidekicks to older cousin Sniff (VMMM009), after an IGI with a wild group in early November, yet the expedition lasted less than a day.
But Stinky seemed to like what he saw, and it may have been his third known roving trip that led him to Alina VLF078 around Christmas 2004. She was just over two years old but the oldest subordinate female at Lazuli. She had suffered her first miscarriage on 6th December and was again ready for a mate. The LH does not show her as evicted during this time, so she probably used a quiet moment (without observers, at least) to sneak off with Stinky. She showed her first signs of pregnancy on 5th January 2005, and was evicted together with younger sister Izzy throughout February - but returned just before Cazanna gave birth (successfully, despite Alina's pregnancy...).
Alina herself gave birth to her first (and only) litter VL0503 on 12th March 2005. It consisted of 4 pups. VLP112 was APRED at 3 weeks old, and VLM109 was abandonned during foraging at one month old. Only HP (VLF110) and Young (VLF111) survived to adulthood.
Interestingly, Young's littermates HP and VLM109 didn't have Stinky, but Sniff as their father even though the two males probably didn't always rove together those days. According to Johanna Nielsen's publication on inbreeding, about 9% of the litters have mixed paternity."
All these years, I thought Grumpy's bloodline was gone foever