There's an English study meet-up in my town, and usually there are around 20 people coming including four teachers, including the four teachers, around 20 people come.

There is an old man named S who is really talkative, and the leader who is feisty inof the meet-up is feisty.

The other day, Mr. S said something wrongeird in front of the others, and the leader wasgot upset and started to yell at Mr. S. ¶
¶
There were already many people at the time, but the two men didn't care about others and kept arguing.

We werefelt really awkward, but couldn't do anything.

Alternatively: It was really awkward, but we couldn't do anything.

WThe reason why nobody didn't stopped their fight iwas because I guess everybody already knew their personalityies, I guess.

If someone triesd to stop them it would have gotten worse.

Alternatively: If someone tries to stop them it would get worse.

However, honestly it felt like the way the leader insulted Mr. S was a little bit nasty.

OPTION A: Two Men Ruined thean English Meeting¶
OPTION B: Two Persons Ruined an English Study Meet-uping

There's an English study meet-up in my town, andwhich is usually there areattended by around 20 people coming, including four [English] teachers.

具体的には、どのようなタイプの教師だったのかを説明します。 彼らは科学の先生でしたか？ 数学の先生ですか？ それとも英語の先生でしょうか？

There iwas an old man named S who iwas really talkative, ands well as the leader who iwas feisty in theis meet-up.

メモ: 会議が終わったので、過去形の方が良いです。

単純な文法または語彙のエラーが発生した場合: The other day, Mr. S said something wrongincorrect in front of others, and the leader wasbecame upset and started to yell at Mr. S. ¶
¶
There were already many people, but the two men didn't care about others and kept arguingthat person. 失礼なことを言われても、次のようになります: The other day, Mr. S said something impolite in front of others, and the leader became upset and started yelling at that person.¶
2つ目の文章をお勧め: These two men ignored others and continued arguing among themselves.

We wereThey made the entire meeting really awkward, but we couldn't do anything.

WhyPerhaps nobody didn'ttried to stop their fight is because I guess everybodbickering because they already knew their personalityies.

If someoneより自然にです: If anyone had triesd to stop them it would have gottenonly made things worse.

We ended up wasting 20 minutes in the beginning of the meet-up/meeting.

However, honestly it felt like the way themeeting leader insult Mr. S was a little bitwas partly to blame because he was so nasty.

There's an English study meet-up in my town, and usually there are around 20 people cominge, including four teachers.

There is an old man named S who is really talkative, and. There is also the leader who is feisty in the meet-uprather feisty.

I think splitting up the sentences is more natural here.
Instead of "feisty", maybe "short-tempered" or "quick to anger" is better?

The other day, Mr. S said something wrong in front of the others, and the leader was upset and started to yell at Mr. S. ¶
¶
¶
There were already many people there, but the two men didn't care about the others and kept arguing.

We wereIt was really awkward, but we couldn't do anything.

"It was really awkward", as in "The situation was awkward"

WI guess why nobody didn't stopped their fight is because I guess everybody already knew their personalityies.

If someone triesd to stop them it would have gotten worse.

After the two men disrupted our meet-up, the leader kicked out Mr. S, and the leader apologized to everyone.

However, honestly it felt like the way the leader insulted Mr. S was a little bit nasty.

There's an English study meet-up in my town, and usually there are around 20 people comingthat come, including four teachers.

We werefelt really awkward, but couldn't do anything.

WhyI guess nobody didn't stopped their fight is because I guess everybody already knewows their personalityies.

If someone triesd to stop them it would have gotten worse.

However, honestly, it felt like the way the leader insulted Mr. S was a little bit nasty.

Or just "Honestly, it felt like..."

There's an English study meet-up in my town, and usually there are around 20 people cominge, including four teachers.

There is an old man named S who is really talkative, and the leader who is feisty inof the meet-up is feisty.

"Feisty" is fine. I think you could also say "short-tempered"?

Besides "leader," you can also use the word "organizer" for the person who leads and organizes things like meet-ups.

The other day, Mr. S said something wrong in front of otherseveryone, and the leader was upset and started to yell at Mr. S. ¶
¶
¶
There were already many people, but the two men didn't care about others and kept arguing.

We werefelt really awkward, but we couldn't do anything.

“We were awkward" in English means that in general, you and others were awkward people. It’s describing a character trait or personality trait.

“We felt awkward,” on the other hand, means that in that particular moment we felt awkward, as if somebody or something in the moment made us feel that way. You can also say, "It was really awkward" ("it" means the situation).

Why nobody didn't stopped their fight is because I guess everybody already knew their personalityies.

If someone triesd to stop them, it would have gotten worse.

We ended up wasting 20 minutes inat the beginning of the meet-up.

After the two men disrupted our meet-up, the leader kicked out Mr. S, and the leader apologized to everyone.

However, honestly it felt like the way the leader insulted Mr. S was a little bit nasty.