With gay abandon
Definition 1 of 1
Pro Tip 1/3Cultural Caution
The word 'gay' has evolved; ensure the phrase isn't misunderstood as referring to sexuality. 
The novel described the children playing with gay abandon, purely meaning carefree joy.
Pro Tip 2/3Emotionally Expressive
Used to convey a strong sense of freedom and enjoyment in the activity being described. 
They threw themselves into the festival with gay abandon, completely lost in the music.
Pro Tip 3/3Informal Contexts
Most suitable for informal situations or creative writing, not formal documents. 
At the reunion, everyone spoke with gay abandon, forgetting the years apart.