Apparently one too many people called him gay over this: he posted a tiktok a short while ago saying he meant what he said and "concubine" basically means slave, apparently hoping the people who follow him don't know better.
Maybe he picked that up in Afghanistan, warlords there keep young boys as concubines and might be disinclined to admit to a random US soldier that the boys all over their compound are sex slaves, so “slaves” is the “softer” term.
Of course, that means that this dude is a-ok with bringing slavery back, so…