Our high school senior is pushing his younger sister away. How can I help them enjoy this last bit of time together?
Your son's behavior represents his gradual preparation to leave home. Family closeness makes it even harder for children to go off on their own. Teens need to begin to put some emotional and physical distance between themselves and their loved ones. (You may very well be next!) He has to pull away emotionally; if he doesn't, it might be too hard to leave. And that would not be healthy. His behavior is a natural part of this developmental stage.
However, I would suggest talking with him about the need to recognize what his sister is experiencing. And vice versa. It is important for his sister to understand that his pushing her away is not really directed at her, but is driven by his emotional need. When a teen leaves home, he looks forward, not back. And he is not mature enough to know that stay-behind siblings can experience a tremendous sense of abandonment. The good news is that if your son and daughter have had a good relationship, chances are good that it will be renewed and/or redefined once he is successfully planted away from home. But the relationship will be different. Older teens (say, 17 and up) don't necessarily want to hang out with their younger siblings. Despite any urges you may have to do so, under no circumstances would I recommend making him hang out with her or take her along with his friends.
You might suggest that your daughter talk with him directly or write a note or e-mail to express her feelings. And you may want to request that he spend some time with his sister, perhaps giving them money to go to a movie, etc. (Understand that he may not want to be "caught dead with her," which you need to respect—but encourage him to express it in a less hurtful way.) Finally, before he goes off to college, you may want to sneak in some activities for the whole family, as well.