Secretly at home with soldier (2,7)
I believe the answer is:
in private
'secretly' is the definition.
(I've seen this before)
'home with soldier' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'with' means one lot of letters go next to another.
'soldier' becomes 'private' (private is a type of soldier).
'in'+'private'='IN PRIVATE'
'at' is the link.
(Other definitions for in private that I've seen before include "behind the scenes" , "behind closed doors" , "Confidentially" , "secretly" .)