Dull friends reaching dead ends (10)

I believe the answer is:

stalemates

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'dead ends' is the definition.
The answer and definition can be both states of affairs as well as being plural nouns.
Perhaps there's an association between them I don't understand?

'dull friends' is the wordplay.
'dull' becomes 'stale'.
'friends' becomes 'mates' (mate is a kind of friend).
'stale'+'mates'='STALEMATES'

'reaching' acts as a link.

Can you help me to learn more?

I've seen this clue in The Daily Express.

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