It's three weeks into summer vacation. ARE YOU BORED YET?
While I'm not so out of touch that I'd EVER suggest a reading program over the summer as a voluntary, go-to, engaging activity for any other than the most stalwart student, there are ways for parents to introduce a little geek into normal leisure activities.
Take television watching for example. There are frequent literary references in shows that the younger generation watches. The Simpsons, South Park, and Family Guy are fraught with allusions to famous quotes especially from the more intellectual characters. Does your student know what that phrase means or where it came from. Lisa Simpson saying "A rose by any other name..." can make Shakespeare relevant.
Video games are another popular diversion which can provide cultural reference resources. My kids played Civilization in their teens. Many of the character and location names stem from actual people and places. Familiarity with the terms can create historical reference points.
Vocabulary building may be the easiest summer activity. Did you notice that the swimming pool at that high school is called the 'natatorium?" Why was that car named 'Intrepid?" What words are used in commercials to make you think the product is superlative? Parental use of a vivid vocabulary can establish contextual clues to new words: "What a beautiful azure sky! The blue is so crisp and clear." "That salesperson was certainly ingratiating. She went out of her way to please us." The trick to contextual definition is to explain the word in the following sentence.
A car game that was a favorite in our family involved changing the wording of common street signs by using alternative vocabulary. "Slow - Children at Play" can become "Proximity of youth in the performance of spontaneous gratification impels immediate deceleration of moving vehicles." The same game can be played with advertising signs or with compliments (or insults that require no profanity).
If every situation is a learning opportunity, parents can sneak an education adventure into even the most mundane occasion.