To those who argued: “swiet –
For the marriage to be valid, you need *only one* of three things: kesef (ring), shtar (kesuba) or biah (yichud). Any one of those being valid and the marriage is valid. So you would need to invalidate all three before even questioning whether the marriage is valid.
Not true. Eidim are neccessary. Stop spouting ameratzus in the name of halacha. “
You only need witnesses to one of them, so if your goal is to uphold the marriage,living together as “man and wife” works. And even if not, she’s a pilegesh (concubine) which isn’t such a bad deal (compared to traditional English law where many bad things happened if you were “living in sin” – including the children couldn’t inherit from either parent).
However if you need to find an excuse to pasul the wedding, one can argue that marriage also needs kavanah (intent) to be married.