Allowing an adoption without a DNA test.

Assuming you still need an answer to this after three months (?; for some reason, I'm just now getting an e-mail about your question), this would really be a matter for the husband to address in the context of actually seeking to adopt the child as a stepfather. There's little you can do to make that happen. But if he *does* take action on doing that, you *could* sign the necessary paperwork consenting to his adoption. (I'm in GA, but I can't believe CA would be any different.)

Hope that helps!