You mention the word ' ex' - does that mean he is no longer your husband ?
Matrimonial rights occur where a house is occupied by a married couple but the property is in the sole name of one spouse. If he is a joint owner he has the right to occupy the property, unless excluded by the court.
Yes, your ex may apply to the Court for an order that you admit him
back into occupation.
You have the right to apply to the Court to exclude him on account of his behaviour. I hasten to add that this is a matter on which you would need legal advice. Yes, you will definitely be advised if he makes an
application to be re-admitted.