Fuck with Milhouse

Lisa finally decided to use Milhouse to lose her virginity. She knows that he will not resist any of her request, since he has a crush on her. She called, and after talking for awhile, Milhouse agreed to lose his virginity with her in his car in the overlook.
The night finally comes, and Lisa and Milhouse start kissing, and later, Lisa goes down on Milhouse. She start to remember what the "make a good blowjob" tips and proceed that it said: unzip the pants, pull down them together with the underwear, grab the dick, stroke it a little and start licking.
Finally, Lisa sucks Milhouse penis, and she did it so well that Milhouse cum after 20 minutes. Then Lisa carries Milhouse to back of his car, makes him sit, and then, Lisa sits over Milhouse, making Milhouse's penis penetrates her vagina. At first, it hurts but then it become more and more pleasurable, and the fuck were frenetic, until both Lisa and Milhouse reach orgasm.
Finally, they rest, and Lisa hears a sound near the car, she see what it is?