...but old age has played havoc with my memory. MC comes from an extended family where the girls get all the attention and the boys get nothing. All the girls have received a new car when they turned 16; the boys have not. So the boys all disappear - some into the military, some to distant jobs and some simply vanish. The MC wins a scholarship to college and tells no one in his family about it; he simply leaves. He befriends and older woman with two teenage daughters. One of his female cousins discovers him in his senior year and asks why all the boys disappear.
He lambasts her. Enough for someone with a decent memory to help or do you need more?