Sorry but I can almost guarentee there is no commercial made holster that will allow the person to hold all 3 phones... Its just not a good idea to make something that only attracts to an increadibly small audience
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You could always have one of them custom-made, because I highly doubt you will ever find anything like that on the open market! I certainly didn't find it when I googled it, and I'm usually a master at surfer shopping! ;-)
you might want to look into getting a "man purse". something small but still versatile (and that doesn't look feminine) that you can use to carry the three phones as well as other things. i have one called the Remora Gearslinger by Maxpedition that works really well...