>>54719
>>54720
1 in 10 foxlets is born with more than a minimum of one tail. 1 in 100 with more than two and 1 in 1000 with more than three and so on.
Foxlets develop and can be born in as little as 4 months, but if their mother is especially healthy and safe, she can delay it to human-like 9 or even 12 months, especially latter puts a lot of strain on her body however, leaving you responsible for almost all chores and work that need to be done. Every extra month usually gives the daughter another tail.
Additionally, energy drain during pregnant sex directly infuses the kit with a part of the absorbed energy, further doubling her development speed inside her mothers womb.
However if your wife is pregnant with multiple kits (as is common for foxes) all that extra effort will be divided by the number of foxlets growing in your wife.
In other words: (Random base chance + extra months pregnant) * (% of days spent draining husband, where 0%=1 and 100%=2) / number of daughters = amount of tails from 1 to 9