Mixing bantams and standard poultry together

[orionburn]

Will a bantam roo still try and mate with the standard birds? We'd like to have the chance to hatch out some eggs next year if possible. But what would we end up with if a bantam sebright mated with an orpington? I figure there is some randomness as to what the color & feather pattern would look like, but are the genetic problems with cross breading like that?

Edit - one other thing. If we end up having trouble with mixing the birds together and end up having to keep our sebrights separate would there be a problem of having a roo penned in with only one hen? I wouldn't want to see the hen get oversexed or hurt.

Thanks to everybody for your replies. You all are great!