Hi Baggy,
Sorry for the delayed reply, I was reading through your past replies (I hope that that is OK.)
You seem like a genuinely lovely person and in all honest, I would stick it out. You've mentioned in your past questions that your partner is family-orientated and testament to this, he's looking out for his daughter in her time of need. I would regret the decision to leave him over this issue.
You don't know how long this situation will last so I believe that you should support him though it and be as selfless as possible, if your relationship is strong enough, and he wants it work then it will.
Sometimes in situations like this I find it therapeutic to give an 'all or nothing' attitude - if it doesn't work, you will know that you have done everything that you can and the problem lies with him.