i do not think you have understood the spirit or intent. that is for people staying over away from the main home. even though he has been away from his home for a period - agreed by LL - his main home is still that. returning to your home is not part of the overnight regulation. might be wrong - but it would go against housing laws and regulations. if he comes and goes, again when he goes away from his home then he is in theory breaking regulations, not when he comes back. but again how this is enforced, who knows... it's about the relationship between you and the lodger, legally the only thing you can do is evict him by giving him valid notice, but hope it does not come down to that. Hope you find an agreement anyway