What to say when he made you feel bad for being nervous

A remark about being nervous is usually less about your nerves and more about how comfortable he is making you the joke. Some people tease because they are unsure how to handle someone who is anxious, and they reach for a quip. Others use it to feel more at ease at your expense. The wording often gives it away. "Relax" and "you're so tense" are about managing your mood. Mocking the specific thing you did, like tripping over a word, is about making you visibly smaller in front of others.

Pay attention to whether he kept going after you seemed uncomfortable. One comment can be a clumsy attempt at humor. A pattern of pointing out your nerves, especially in front of other people, is a sign of how he will treat you when things are tense. Your read on the comment should weigh the setting as much as the words.

The reply needs to say plainly that the comment landed badly, and it should name the specific thing said rather than a general feeling. Something like "that comment about being tense stuck with me" carries more weight than "you were being mean." Naming the words keeps the focus on what happened and gives him nothing to dispute about your character.

It also has to avoid reopening the question of whether you were nervous or whether that was a reasonable thing to feel. Nerves are not the problem here, and a good reply treats them as ordinary. Say what you want from him going forward, such as being told to relax when you are already anxious is not helpful. Then stop. Your reply should be short enough that he has to respond to what you wrote, not to a defense you mounted.

After you say it, leave room for him to answer. A decent person will usually acknowledge the comment, even if awkwardly, with something like sorry, I didn't mean it that way or yeah, that was a dumb thing to say. That response is the signal you are looking for. A deflection like you're overthinking it or it was a joke tells you he is not going to take your feeling seriously.

If he does not respond, or responds with another joke, you have your answer about how he handles feedback. Do not follow up with a second, longer message trying to get him to see it. One clear message is enough. If the conversation keeps going, watch whether he treats you differently in the next few interactions. The next time you are nervous, that is when you will learn whether he has changed.