Awww isn't Shizuma such a lucky guy? He doesn't need to do anything. He has Minato, who has to teach Shizuma how to be a decent boyfriend. He doesn't need to set boundaries, Minato could suck it up anyways. The dude has a perfect boyfriend who he doesn't even have to gaslight. Minato's own trauma makes him gaslight himself into believing that his totally and perfectly justified concerns are actually unjustified. You're such a lucky guy Shizuma, you can hide all your wrong doings under the "Minato is insecure because of his trauma" rug.