Bluethroat Triggerfish pair

I have a 75g reef tank and I am going to add a pair of bluethroat triggerfish. My Lfs currently has a male. I was wondering if I could add just the male and add the female in about a month when my lfs gets one in stock. Or do I need to add them both in at the same time? Also, Do I need to put them both in an accumulation box to pair them up, or will they do it naturally