Beth watches the white male mink and his brown-furred sister nuzzling and churring at each other in comfort. She decides she will keep the princess and prince in these forms... clearly they care very much for each other.
Then a mischevious idea pops into her head. "Hmmmm... I think it would be more appropriate for females minks to have white fur, and males to be brown"
With a quick zap of magic, Beth alters the genders of the minks. Palador's male penis sucks into his body, leaving a fleshy female vagina... while Galla's genitals develop into male equipment.
It happens so fast that the minks don't even realize their sex changes.
"Now," thinks Beth, "how might I get them to mate..."