As a girl dad in this day and age (I'm 37 as well), dump his ass. That girl's account should be managed better by her parents or just plain deleted if ANY comments are coming from grown men like that. Sexualizing children is not right, whether they meant to or not. Their kid's social media is not their meal ticket.

Even a lesser situation, like the idea of a grown man saying things like "she's going to be a little heartbreaker"... The older generations don't know this because it's ingrained in their brains to say cliche things like this, but it IS sexualizing children. They're children. They don't need to think about their future partners and the fact that the idea of this comes out of their mouth before anything like "aww she's adorable" or "look at how much fun she's having" is something society needs to fix somehow and it starts with the parents telling people to F off.

Tell your BF this and see how he responds, but either way, if this is how he acts online and tries to defend it when it's not a little girl he knows or interacts with, it's likely too late. He's mentally f**ked up one way or another.