Feeling stupid, son pushing daughter out (5)
I believe the answer is:
sense
'feeling stupid' is the definition.
'sense' can be an answer for 'feeling' (I've seen this before). I am not sure about the 'stupid' bit.
'son pushing daughter out' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'pushing daughter' becomes 'sene' (I am not sure about this - if you are sure you should believe this answer much more).
'out' is an insertion indicator.
's' going inside 'sene' is 'SENSE'.
Can you help me to learn more?
(Other definitions for sense that I've seen before include "smell, for example" , "Realistic attitude" , "Tenor" , "Practicality, often common (5)" , "Become aware of" .)