It wasn't as though they hadn't tried to come to an agreement. It was just that Cory seemed to be channeling his Nana Booboo, picking names like Ethel and Miriam, while Shawn was apparently determined to show the world his trailer park roots. And no matter what Shawn threatened to with hold or for how long, they were NOT using Veronica if it was the last thing Cory ever did.
Everything - the arguments over names and living situations and Cory's possibly still lingering feelings for Topanga - melts away as they take turns holding Isabel, her tiny hands grasping at their fingers. Shawn's the one to cry, although he manages to wait until they're in the car in the hospital parking garage. They manage to wait until they're home before they have ecstatic 'We're parents!' sex, but immediately feel guilty afterwards, thinking that it's not the kind of thing most people do their first night as parents.
They never argue about who's straighter, because Shawn makes a living writing angsty emotional poetry and Cory does things like coo over little dresses and matching booties while window shopping. Shawn doesn't know whether to cry, groan, or just start chiming in. Eventually he chooses the latter, because no way in hell is he letting anyone, even Cory, put a dress that ugly on his little girl.
Neither of them sleep for a good three months, and they have only themselves to blame for that because Isabel is the most easy going, peaceful child ever. When Cory's parents come to visit they smile and play with her and tell them how lucky they are, that none of the Matthews children ever behaved this well. Shawn nods and agrees, thinks that Isabel is probably just going easy on her parents, and somehow knows that they probably would have had matching nervous breakdowns if they'd spent the last few months with a colicky, difficult baby. He can already tell she's considerate like that.
Cory thinks that she looks like Shawn, but he's really just using the hair as proof, and Shawn thinks she has Cory's eyes. They don't really get the chance to argue the point much because whenever they do people start to roll their own eyes or (in morgan's case) make gagging noises, and even when its just them and the baby Isabel seems to give them the stink eye if they start in on the Whose Nose Is That? game. Topanga doesn't seem to mind that they don't include her in these comparisons, although she clearly has a huge soft spot for the little girl, and makes a point to vist her on the way to work everyday.
Cory knows that babies often cause stress to a relationship (his own parents reminded him quite often) but his relationship with Shawn has never been better. He thinks it's because now Shawn feels like there's something tying Cory to him, like two plus decades of friendship and several years of intimate relations isnt enough on its own. Shawn knows that Cory would die before leaving his little girl, and Shawn feels the same, and now there's only so much distance they could ever possibly achieve. Its very dysfunctional, but considering how much of Shawn's adolescence was spent sleeping on park benches and crashing at other people's homes he can't hold it against the guy for wanting some proof of security. Cory has learned not to take it personally.
Then about six months later Shawn's career really takes off with a short story that gets a lot of attention and Cory could probably pinpoint the exact moment when the wheels in Shawn's head start spinning out of control. He's unused to the idea of things going well, the notion that nothing's wrong. The mental psychout ends with a two day disappearing act that has Cory out for blood when Shawn turns up stone drunk at two in the morning, rambling about his parents and his trailer park adventures, a few of which Cory has never heard before. The next day Cory makes as much noise as possible the whole day, perversely glad every time he hears the toilet flush. He slams the door on his way out, leaves Isabel with Topanga, and heads back to the apartment, not wanting his daughter to hear the yelling, whether or not she'd ever remember it. The argument itself is actually pretty short, because neither of them was particularly surprised by the turn of events, and although nothing is officially resolved they both know the next freak out will probably be Cory's. They take advantage of Topanga's babysitting and have sex twice before falling asleep, waking up only when Topanga walks into their bedroom and deposits the baby next to Shawn, who is curled up facing the door with Cory spooned behind him.
Shawn puts his hand around Isabel's little head and says hello, kisses her forehead, and feels Cory smile into his shoulder.