Could be used to say, It's really "happening", which in this case means it's really cool, it's off the hook, it's a lot of fun...just like hella cool would imply that it's really cool, hella happening could be used in a simillar context to mean pretty much the same thing...
an attempt to change the topic from accusing your boyfriend of unwittingly claiming to be gay when in reality he was simply trying to respond, cleverly, in the regional lingo of your native country.
m- "g'day, banana bender!"
f- "are you coming out?"
m- "what? no, it means 'someone from queensland'"
f- "it means 'gay guy'"
m- "..."
f- "let's try this again: 'hello, happy monday!'"
Happy people go to hell is a saying originating from online forums. It is used by anybody who is not a normie especially those who just experienced something very bad. Also used as slang in groups of friends when a couple is spotted.
Friend A (single): "Look at Nathan and Cora over there, I still can't believe that they are a couple"
Friend B (single): "Happy People Go To Hell"