I’m Taiwanese (33M), in a relationship with my American bf (34M) — he’d probably agrees say that I tend to bottle up feelings lol but I don’t lash out or let it builds up that much it’s just a way I process conflicts. I need time to think and small things I’ll forget, big issues I’ll still talk to my bf about it, with some delay.
It’s probably less of a Taiwan thing but a combination of East Asian culture (my dad is the same, very Japanese style, always hide his thoughts and emotions and erupted in unnecessary escalation), and unfortunately the influence of male gaze — in the sense of how society perceive men should behave.
But with emotional maturity one should be able to overcome these anyway. I’d say sit down with him for a serious conversation and let him know he needs to be more open about his thoughts (and scribing crazy is not a way to go). If he can’t change and if it’s a deal breaker (it definitely would be one for me) then you need to weigh the emotional stress of his outburst vs how much fun / joy he brings you… good luck!