Why? What makes you say childhood trauma?!?!?!
Oh, it's just the usual BL cliché whenever one of the character is being too promiscuous with whoever and whenever. Most of the cases it's due to SA or violence in their past. I hope it's not the case here, it would be refreshing to see the uke being a sexually liberated man with high libido & a touch of psycho vibes. Since the story is only 5 chapters long I bet it has nothing to do with any childhood trauma
Ah okay...you make a good point.
I sense childhood trauma from that uke. Or maybe he's just a proud unapologetic whore?