Alright, I am writing this for “apologetics” for the 21st century.
Many of us will have friends who are or who will have children out of wedlock.
Too many brave women chose life and too many young men fly from the responsibility. The latter are blameworthy but only to an extent in certain situations (and the former are praiseworthy insomuch as they chose life: to be sure, she MUST wait - men WILL wait if you make them and adore you for it!). Regardless, the man presumed a childless relationship. But now there is a child.
Be that as it may. For younger men (or women) who know a man who has fathered a child, what do you tell them?
Tell them this: you are blood now. The woman who has had your child isn’t a “random” anymore. She is blood. Through your son/daughter, she is your blood. You may not like or want her (in “that way”) - but she is your blood now. You have tons of family whom you love but don’t care much for in a voluntary/choice (let alone romantic) way - but you still love them.
Therefore, see her as what she is, your blood. Love her at least like family. The child, the mother, are now your blood (and tell them YES, you ARE related to her now through the chid!). Tell them it is impossible to get dishonour from taking care of your blood; moreover, it is to this day hugely honourable to look after your blood.
Say that no one is forcing you to marry her or whatever. But remember that she is your blood now. Therefore it is terribly dishonourable to neglect her. Love her at least like a cousin.
These are social challenges we will have to deal with. We are pro-life or, better, pro-existence. The phenomenon of the single mother has already hit most Western countries like a typhoon: the United States will feel it soon enough. It is going to challenge our charity and our commitments. I think we need to stand firm and beside human society: I think we need to have as a “Plan B” that the marriage culture might collapse. We need to foster environments by our lives and examples that can bring it back: especially by our own witness. That storm has already hit most places. It is going to hit the U.S like a tsunami soon enough. This is just my personal and practical advice for my friends in the States.