Puritan and saint drinking wine — they may be in bed (9)
I believe the answer is:
primroses
'they may be in bed' is the definition.
The definition suggests an adverb but the answer is not.
'puritan and saint drinking wine' is the wordplay.
'puritan' becomes 'prim' (prim can mean puritan).
'and' is a charade indicator (letters next to each other).
'saint' becomes 's'.
'drinking' indicates putting letters inside (inserted letters are consumed or drunk).
'wine' becomes 'rose' (rose wine is a kind of wine).
'prim'+'s'='prims'
'prims' going around 'rose' is 'PRIMROSES'.
Can you help me to learn more?
(Other definitions for primroses that I've seen before include "plants" , "Promisers or pretty yellow flowers" .)