Re: Husband and daughter
OP if you read this I understand what you saw shocked you and you ran because you didn't know how to deal with it. Possibly that's the same reason you are not returning to this site, you realize you didn't react appropriately and now you are ashamed and don't want to deal with the harsh judgement.
You still need to do everything in your power to make this right. It doesn't matter if your daughter is the age of consent or not, what matters is your husband, the man who also served as a father to this child has abused his position in a sickening way. You have to realize this didn't just happen unless he was forcibly raping her at the moment you saw them, more than likely he has been grooming her for years, and probably abusing her for some time now.
Call the police, get a protective order covering you and the child, have him removed from the home, prosecute him if possible, divorce him as quickly as possible. You have an obligation to protect your daughter, this isn't about you feeling ashamed or embarrassed, you need to rescue your child from this man regardless of how it affects your feelings. Both of you need to get into counseling, this is a big big deal, you can't sweep it under the rug.