| Quote #1
A woman had to yield him what he wanted, or like a child he would probably turn nasty and flounce away and spoil what was a very pleasant connextion. But a woman could yield to a man without yielding her inner, free self. (1.15)
Connie manages to have sex with her first boyfriend without losing some sort of "inner, free" part of herself. In other words, she has sex with him but it doesn't mean anything. It's just bodies.
| Quote #2
It had a thrill of its own too: a queer vibrating thrill inside the body, a final spasm of self-assertion, like the last word, exciting, and very like the row of asterisks that can be put to show the end of a paragraph, and a break in the theme. (1.17)
Connie thinks about sex—orgasm, specifically—as though it's punctuation on a page of writing. Why have sex when you could just sit down at a typewriter? (We suspect that D. H. Lawrence spent a lot of time in front of typewriters.)
| Quote #3
It is curious what a subtle but unmistakable transmutation it makes, both in the body of men and women: the woman more blooming, more subtly rounded, her young angularities softened: the man much quieter, more inward, the very shapes of his shoulders and his buttocks less assertive, more hesitant. (1.21)
Despite what your parents may have told you, it's unlikely that a double-blind, peer-reviewed study would find any visible difference between a virgin or a non-virgin. Not the kind that would make a guy look less confident, anyway.