Guests with sex appeal wearing masks (8)
I believe the answer is:
visitors
'guests' is the definition.
(I've seen this before)
'sex appeal wearing masks' is the wordplay.
'sex appeal' becomes 'it'.
'wearing' becomes 'visors' (I can't explain this - if you can you should give a lot more credence to this answer).
'masks' is an insertion indicator (mask can mean to cover up or conceal).
'it' inserted within 'visors' is 'VISITORS'.
'with' acts as a link.
Can you help me to learn more?
(Other definitions for visitors that I've seen before include "Holiday-makers or guests" , "Callers or tourists" , "away team" , "They call socially or on business" , "'Callers, guests (8)'" .)