Girlfriend won't marry me or double-barrel our son's name.

[drmarcus]

Our son is due next month. We are not married. I'd really like my surname to be included too but she won't have that. I would also like to marry her and offered to take her name but she doesn't want to marry? I'm beginning to wonder if she has other motives :( does this behaviour sound odd to you at all?

This is an example of why being married before having children is beneficial. Then the OP could register the birth and double barell his son's name.