Ordinary family dynamics in the Saiyan community. Especially after a baby is born.
The parents all take turns feeding their little -bottomless barrel- bundle of joy, and the baby gets well fed.
Any excess milk is used for other things~
Cute Saiyan babies sleep like possums. After they become too big for their tail to hold them comfortably, they get a nest of their own. And when they reach their second age (our definition of puberty), they are free to join the adults in their nest.
(Gine doesn't have a bite mark yet because he isn't Bardock's breeding mate YET.)
Incest and monogamy are not concepts that exist in Saiyan Culture. Sex is not a 'forbidden thing'. It's a great way to exercise, get a natural high, form stronger pack bonds, increase base ki (I'll explain this someday), and just have fun, ya know?
So from our pov, it's incest, but from a Saiyan's pov, it's just connecting, family love or what have you.
Mind you, all Saiyans that participate in sexual activities are sexually mature. A Saiyan who doesn't have their sex hormones developed (aka child) is just not attractive. Saiyans are scent oriented as we are visually oriented. They recognize themselves more by scent than appearance.