Intimate conversation to bolster lecture (6,4)
I believe the answer is:
pillow talk
'intimate conversation' is the definition.
(I've seen this in another clue)
'bolster lecture' is the wordplay.
'bolster' becomes 'pillow' (I've seen this in another clue).
'lecture' becomes 'talk' (synonyms).
'pillow'+'talk'='PILLOW TALK'
'to' acts as a link.
(Other definitions for pillow talk that I've seen before include "Bedtime conversation" , "romantic comedy film" , "Conversation in bed" , "Conversations in bed" .)