Praise be to Allah.
Indeed it is obligatory for the woman (in this situation) to withhold herself from that intimate relationship, and the opposite also applies [i.e., a man should withhold himself from his wife if she does not pray]. Allaah says (interpretation of the meaning):
“… Likewise hold not the disbelieving women as wives…” [al-Muntahanah 60:10]
It is not permissible for a Muslim woman to stay with a man who does not pray at all or does not pray most of the time; she has to leave him and not stay with him, because he is a kaafir who has gone beyond the pale of Islam. We ask Allaah to keep you safe and sound.