Can someone please check my grammar? Thanks

I'm writing a fictional story where this guy is telling to an other guy what happened at a Halloween party some years ago.
The guy who's talking speaks in an informal way.

Dialogue:

"Everybody kept asking 'em what were they dressed as, so, at the umpteenth person who was asking his girlfriend about their couple costume she just simply replied: 'I'll show you'”, he said, in a high-pitched mocking tone. “So she starts running towards him and he was supposed to catch her but instead – he started to laugh again - ...they both plop down on the floor! It was hilarious!!” he said, snickering.
Brian started to laugh sneeringly along with his friends. “In my defense, I was a bit tipsy and she had gotten a bit fat.”

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Any corrections? Suggestions?