So I'm all for Harry/Harem. I mean, He is the chosen one, and the last heir to a purportedly wealthy and powerful Pureblood family, not to mention being Sirius' heir as well, so he would feel the need to have many children to make sure the line(s) don't die out (or what ever. I'm making stuff up at this point, you know?), or perhaps he can't choose between the girls that he loves best and they're not about to make him choose, for what ever reason of their own that they have. I mean, I'm fond of partner-swapping!Harry Potter stories(both male and female swapping. bring on the boy and girl slash bb.), not that I've really read many good ones and none recently.
But. When I can't keep the girls straight because there are more than, say, 50 of them (and most of them are OCs).
And instead of it being a "Harem" harem, where he basically has sex with them for alliance purposes, they're all full "bonded".
And all of them are in love with all of the others, regardless of how long they've known each other and they can all read each other's minds and share knowledge after Harry's (apparently) magical cock penetrates them.
And they all get pregnant at right about the same time, because Harry has super cock powers and can impregnate 50+ women in one night.
And he kills all the men and inherits their women and properties because since the purebloods are all related he's next in line.
It gets a bit ridiculous.
Ok. More than a bit. I like the HP characters. OCs are ok, don't get me wrong, but I feel that there should be a very good reason if Harry isn't with some one that he actually knows. Like his friends are all dead. Or everyone is brainwashed by Dumbledore to turn their backs on him. Or if there's an OC I want to see them meet and become friends and get to know each other before "falling in love". Make me believe it.
Also, it is COLD.