My friend kind of piss me off

Context : i work with a friend on making shorts films, we write the story, film the scenes, and he does the editing.

Here's the thing, often when i said a thing, or propose an idea, he says stuff like "you're dumb", "you're so stupid" as a joke, he likes to put me down as a joke, i think he's ruining the creative process, because now i feel that unconsciously i think too much before saying a thing. As i often i keep this to myself, i rarely share my thoughts about what annoying me to people, and that's my bad, i know i should express my thoughts more, but i often feel that it will be useless, that "changing" people never work. So i never do it. That's it.

I don't think he does that only with me, he's whole friendgroup seems fill with a lot of teasing, i do teasing but very light compared to them. He has a lot of qualities, i can really share the thing that saddens me in life and he'll listen.

For example he's the first guy who i told that i was attracted to men and he helped me not feeling judged. When i was so scared to assume that to people

i also think i'm very sensitive even if i don't show it to people, they often tell me that i'm an insensitive guy which i clearly not agree.