I feel like, reading between the lines, you’re thinking maybe he might get her pregnant with his fourth, perhaps a third marriage in the cards, and that you wish it’s you in this situation and quite possibly would be you had you played things closer to the chest. Just remember he already has three children to think about and that you and any child you have with him would be getting a quarter of his
to share, in the best case scenario where he is a good dad.
Please forget about him and throw your line back out again