WTF he shoulda known something was up when she didn't open up her mouth, and proudly show what a good girl she was by swallowing it up. What self respecting woman doesn't do that?
Courts have consistently ruled, that while the mother may have intentionally misled the male, the welfare of the child supersedes all other concerns.
This has even gotten so far, as a male after donating sperm at a sperm bank, being liable for his subsequent child.
In other words, keep your pants zipped unless you are SURE you can deal with the consequences!