"I don't understand why that's a thing!" Mark exclaims, genuinely baffled even as the both of them continue at a faster pace than before. In the back of his mind, he wonders if this might be a better impetus and distraction for Rachel than anything else, even the briefest mention of her kid being put at risk, but the topic itself is interesting to Mark as well. "You can usually create another kid, a baby doesn't even have time to differentiate itself and be an actual person, but there are some twenty years that have gone into you and making you this unique person. Why would I want to choose someone who doesn't even have a personality before you? That makes no sense."