The most common and most likely answer to this crossword clue is the 3 plus 2 plus 3 plus 6 letter word DOG IN THE MANGER
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More clues leading to the result DOG IN THE MANGER
- Possibly bitch furiously about them, being of possessive type?
- In this arrangement, we might see dingo anger them!
- Drink them after party to irritate spoilsport
- Gather men tipsy after party spirit — such a spoilsport
- After party drink those people annoy someone who denies others pleasure
- Party and drink, they infuriate one showing obstructionist attitude
Buddy explains!

The straight part
We know that "spoilsport" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case spoilsport = dog in the manger.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.