My boyfriend does not have a return ticket from Shanghai?

Hi there I have got a job teaching English in Shanghai from Australia, leaving on the 26th April. Now my boyfriend will be coming with me for a while on a tourist visa and then will go off and do his own travel. My question is: what will he do about the visa as it states that he must have a return date on it? Also can he stay 3 months leave China and then come back again as a tourist multiple times? Many thanks