Trust concerns with degrading my sub

Hey all. I’m a domme and one of my subs keeps asking for degradation and humiliation, which we’ve done in the past. He responds well in the moment, but becomes extremely insecure days and weeks after the fact. I understand that aftercare can be an extended experience, especially when inflicting emotional pain, but my concern is that he’s internalizing these scenes. We’ve discussed what’s off-limits verbally and I will always respect those boundaries. I enjoy aftercare and reassuring my subs, but having him bring up the things I’ve said mid-scene weeks later makes me hesitant to degrade him again. He’s requesting another humiliation scene tonight and I told him my concerns, but he’s adamant that he can handle it emotionally. Does anyone have advice?