The 500-pound Kifu treated Aspinall gently most of the time, reaching into his pockets to see if he had any more snacks. But he also clamped his jaws around Aspinall's shoulder. It's normal gorilla horseplay, which Aspinall likes to call "love bites."
"Kifu plays very gently with me," he said. Then he added, laughing, "He knows I'm not after his women."
It is Sounda, a female and mother of two, who will hold his baby daughter Freya. The keepers say she is the best mother in the zoo.
Aspinall agrees, "Sounda is the gentlest of gorillas and would never, never harm any, any of my children." Gorillas do not, by their nature, attack humans. But in the complex gorilla world, there is enormous potential for misunderstanding between man and animal, something we discovered very quickly here.
As our cameraman filmed through the bars, one female gorilla approached quietly and then grabbed keeper Steve Perry by the neck. The gorillas erupted in a frenzy. Another keeper had to drag Perry away.
"I got too close because there was food on the scene," said Perry. "Had there been no food there probably wouldn't have been an issue there really."
Aspinall himself was attacked a few years ago, when another silverback thought he might be a competitor for the affections of a gorilla female. For his baby daughter, he and his girlfriend, Donna Air, consider the risk to be small.
"Any mother is always apprehensive, as you can imagine, but she's fully supportive of me," he said. "She's seen me in with the gorillas a hundred times. It's just I have complete faith and trust, as, as, you know, I love these gorillas and they love me."
For more information about Howlett's, its charity and what it does to fight the declining gorilla population, go to www.howletts.com.