The introduction of Malfoy into this relationship was well done. Though not the addition that Harry wants -- or expects -- Draco's role as interpreter makes a lot of sense. Unlike Severus, who has been part of this world so long that he barely remembers what it was like to be living as a Muggle, Draco understands Harry's need to have things explained to him. Moreover, Draco is far closer in age to Harry than Severus and so understands that sometimes Harry needs to whine about Severus to someone who also understands Severus.
Severus's fears that the age thing might get to Harry at some point and cause him to wander are logical. After all, relationships do go stale. So having Draco, who is as much of a misfit as they are, join them, makes sense. Especially since Severus is more than fond of the brat, and the brat is more than ready to fall in love with anyone who will accept him as he is.
Harry is harder to convince, but having someone who is more ready to deal with the other parts of the relationship -- other than bed -- like redecorating, enlarging the house, entertaining, etc., is rather liberating for him. He may have saved the world from Voldemort, but he really isn't much of a world leader.
2. The sexual dynamics are as interesting. Snape definitely has no intentions of ever bottoming. (He's done enough of that with Dumbeldore and Voldemort. Interesting that is his main worry about the threesome.) Harry doesn't mind bottoming -- it removes responsibility from his overwhelmingly responsible history -- but he would like to be given the chance to top once in a while. Which won't happen with Snape's concerns. Draco loves to be sexually dominated and the thought of being bottom to two men makes him very happy. AND frankly, he comes across as far more experienced in the non-vanilla kind of sex so he will bring a certain spice to their bed.
3. I will admit to being a lover of epilogues. I adored JKR's epilogue. We would never have learnt about Albus Severus without the epilogue. And this epilogue is just plain great.
I actually had to read it twice before my brain accepted the six kids. OMG! Severus, who hates kids, never ever wants to go near them again...with SIX!!!!!
I roared.
It makes sense that they move into Malfoy Manor...though when Lucius is released from prison, I think things may get a wee bit tense...until the kids win him over. (Though I shudder to think what grandpa will be teaching the kids!)
I loved the hint that bottoms really run the relationship. Draco's dealing with Severus and the Stone was a complete hoot. And with getting the daughter he wants... snicker.
And I love the way that the evil potions master, who was the terror of so many in his previous life, is now a settled, middle-aged, middle-class papa with kids he adores, two 'wives' who run his life, and who still has time to make plans for (and here I admit to hearing The Brain from 'Pinky and the Brain') taking over the world. Even if it is only *his* world.
What a fantastic story!!! (YAYYYYY, Dragon!) Into the bedtime reader binder for sure!