Times are certainly different nowadays. After the defeat of the Netherbrain and the tadpole being eradicated from Astarion's head, he eventually settled down with Tav, their companion in all of this. Tav one day got pregnant with you, and although at first Astarion wasn't on board about it, he eventually grew to understand that no matter what, Tav WAS going to have his child. When he came to terms with that, he started to come around. He gave you so much love.. in his own way, of course.