French phrase
Je me réserve ~.
Meaning
I reserve ___ for myself.
When to use it
It keeps an option or right open for later. This can delay an immediate decision without sounding too formal.
Example dialogue
Je me réserve le droit de réfléchir.
I reserve the right to think it over.
Très bien, dis-moi quand tu as décidé.
Very well, tell me when you've made up your mind.