The general assumption by those not familiar with BDSM, Kink & Fetish, is that the Daddy/Babygirl relationship is incestuous.
It’s not. It’s a Domination/submission (D/s) relationship.
On the D/s spectrum, Daddy/Babygirl is a warmer and more loving relationship than Master/slave. Play may be less strict, with more laughing and more cuddles. Often the Babygirl seeks the approval of her Daddy, wanting to make him happy by performing acts that please him. The Daddy will in turn take care of her, giving her whatever special treatment she enjoys as a reward for her good behavior.
One thing is constant: The Daddy calls the shots and the Babygirl does what she’s told. There is some variation depending on the Limits set by the individuals involved. Some couples like rough play, some are into Age Play, and some Babygirls are horrible Brats.
Now – If the individuals involved have incest as a fetish, then they will pretend their relationship is incestuous – even if they are not actually blood related. Remember, it’s just pretend.
The Daddy/Babygirl relationship is not limited to older Daddies and younger Babygirls either. They can be the same age or in some rare cases have an older Babygirl and a younger Daddy.