TolkienGoddess said:
From reading the HHB, I got the idea that only Susan, not Lucy, was being sought after as a bride. I don't know if it was here, or another Narnia forum that I read, but someone said that Susan could not come back to Narnia b/c she had been sexually active.
I agree with ReepicheepFan here - there's no indication that Susan was promiscuous, either in Narnia or back in England (though Lewis had no illusions about just what girls who obsessed with "nylons and lipstick and invitations" were capable of). She was sought after because she was so beautiful - a point which was brought out in several books. Lucy was sought after, too ("all princes in those parts desired her to be their queen") - she just wasn't as interested.
Lewis would find it telling that someone would even think that sexual sin would be the "door-slammer" for Susan. In
Mere Christianity he points out that though the modern world
thinks that Christians believe sexual sin is "the biggie" - i.e. the worst sin - the fact is, it's not. The modern world hears a lot of chastisement regarding sexual sin because it violates those laws so flagrantly, but it's not the worst sin. Pride is, as he makes clear in the chapter
The Great Sin. In fact, even if Susan were breaking God's laws regarding chastity, I don't think Lewis would have considered those her greatest offences. Her self-absorption, disregard for the blessings she had received, and obsession with lesser goods would have probably come before that, as well as her (probable) vanity.
If you can, see if you can run down a copy of a short story called
The Shoddy Lands by Lewis. It's very interesting.