Slack-jawed at first, getting affectionate with royal (7)

I believe the answer is:

gawking

'slack-jawed' is the definition.

'first getting affectionate with royal' is the wordplay.
'first' suggests taking the first letters.
'royal' becomes 'king' (a king is royal).
The first letters of 'getting affectionate with' is 'gaw'.
'gaw'+'king'='GAWKING'

'at' is the link.

I've seen this clue in The Everyman puzzle in The Observer.

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