Boy! Speech at The Bar is first-rate for someone lying and feeling the heat (10)

'boy speech at the' is the definition.
I know nothing about this answer so I can't judge whether this works.

'bar is first-rate for someone lying and feeling the heat' is the wordplay.
I cannot quite understand how this works, but
'bar' could be 'lounge' (I've seen this before) and 'lounge' is found within the answer.
'someone' could be 'sun' (sun is a kind of someone) and 'sun' is found in the answer.
A single letter 'r' remains which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?