The most common and most likely answer to this crossword clue is the 3 letter word APR
I've seen this crossword clue in The Daily Telegraph
A
P
R
Buddy explains!
The straight part
We know that "social event there" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case social event there = apr.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.
What does APR mean?
APR proper noun- The fourth month of the Gregorian calendar, following March and preceding May. Abbreviation: Apr or Apr.
- A female given name from English; used since early 20th century.