The baby, easily visible as a boy because it wasn't wearing anything, sat on Buffy's lap and looked puzzled. He cried out of hunger and looked around for a food source. Buffy's breasts were there just above it and they were getting full of milk too fast, but they were covered by the blue bikini.
The baby tugged at the bikini and Buffy finally said "Don't poke me! You're being a pest." He just tugged again and Buffy replied, "Oh, fine." She unfastened the bikini and let it hang loose so the baby could get to her breasts.
Buffy's hungry baby went for Buffy's nipple, which would have been fine except that Buffy had to move the loose bikini top aside and it ended up draped over the baby for a few moments. Then Buffy's newborn son began to grow....