Is it normal to exploit other people’s weaknesses to put them down and feel better about yourself?

Is it normal to exploit other people’s weaknesses to put them down and feel better about yourself? I’m going through something difficult and I need to share. I’m currently doing an internship at a company, working in a pair with someone who is very competent and socially confident. From the start, I’ve felt like he exploits my weaknesses to put me down. I have situational stuttering: normally I speak fine, but in front of others, I lose my words. He knows this and seems to use it against me: he interrupts me, asks unexpected questions in front of the managers, raises his eyebrows when I speak little, and constantly comes back to question me. This isn’t jealousy. I don’t want to “beat him,” I just want to work peacefully. But I feel crushed, invisible, like I don’t have the right to speak or exist in the room. On top of that, he continues making advances and chivalrous gestures since university, which makes me uncomfortable. I feel like all of this is just a way for him to exploit my weaknesses to put me down, while showing off and “shining” in front of others. I still can’t speak easily to men in these contexts, even just to ask simple questions, whereas he has had opportunities to learn how to handle his pace in public. Today, he monopolizes attention during interviews, speaks loudly, tells his achievements, and I remain frozen, unable to speak. I feel guilty for being “fragile,” but I know this isn’t jealousy. I just haven’t had the same experiences yet to learn how to handle these social situations. So, is it normal for some people to exploit other people’s weaknesses to put them down and feel better about themselves? Has anyone else experienced this, and how did you handle it?