Father is with child? It's really exciting (7)
I believe the answer is:
frisson
'really exciting' is the definition.
I can't judge whether this definition defines the answer.
'father is with child?' is the wordplay.
'father' becomes 'fr' (abbreviation as in a priest's title).
'with' is a charade indicator (letters next to each other).
'child?' becomes 'son' (male child).
'fr'+'is'+'son'='FRISSON'
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for frisson that I've seen before include "Kick" , "Shiver of excitement" , "A shudder or thrill" , "Shudder of excitement" , "Emotional thrill" .)