She thinks to herself how early on she had to deal with sexuality. She was twenty one and she'd been looking at porn since at least age eleven, how many relationships she's had that were dominated by sex. Outright removing sex didn't seem like a good option, she didn't want to go back to the way she was before puberty forever, but she realized it would be nice to have a bit longer...
She simply decided to push when humans sexually develop back by thirteen years. Instead of puberty starting around ten it started around twenty three. People still developed in all of their non sexual traits at a normal time, they would be adult sized at the same time, and while they'd lack the effects of estrogen or testosterone they'd still have adult bodies at the same time, as well as mature brains, but the changes from puberty would all happen in their twenties, long after they'd grown up. Everyone would already be adults by the time they had to worry about things like body hair, periods, orgasms, and the ability to have children. As a bonus she'd also have the effects of old age take longer to set in, so humans have a good amount of time after puberty to be young and hot.
She realized that soon she would be a pre pubescent adult, something that would be considered completely normal. A twenty-one year old woman with no secondary sex characteristics. When she began to think about it she started getting wet, but pretty soon she'd be months away from her genitals being able to do that. She realizes that soon she might not even be horny at all.