Like Prince Andrew with sweet lass dancing? (9)

'sweet lass dancing?' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'like prince andrew with' is the wordplay.
I cannot quite see how this works, but
'with' could be 'w' (abbreviation) and 'w' is present in the answer.
The remaining letters 'seatless' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?