why does it smell like bleach?...

hopefully you all know what im talking about. not me but HIM! his semen smells just like bleach weve been together a year and its ne et changed i thought maybe it was a temporary thing... extas - he smokes (pot & cigarettes), eats terribly. any reasoning? solutions?? help!! i gag from the smell and i feel bad :/ sometimes i want to please him and finish the job but i just cant.