"Afternoon delight" is a phrase that is often used to describe spending intimate or romantic time together during the daytime, usually in the afternoon.
Trying new things with your partner bonds you in a new way — especially when your activities are adrenaline boosters like watching a scary movie, taking a risk of some kind (for example, cutting out early from work for a little afternoon delight?) (mindbodygreen.com)
Oh, you want to know where I had an intimate sexual encounter and if it was a session of afternoon delight or a romp in the wee hours of the morning? (babygaga.com)