Sessions blocked The Domestic Minor Sex Trafficking Deterrence and Victims Support Act of 2010. Think Progress wrote an article calling him out for it. ICYMI, Think Progress is a branch of Center for American Progress, founded by John Podesta.
In the article (don't worry, it's an archive link), they state:

Sessions is pushing back against claims that he believes child victims deserve to be arrested as prostitutes, something the conservative Concerned Women of America alleged.

EDIT: I just realized how much Think Progress twisted what was said (typical): to clarify, this Woman's group does think underage sex workers (slaves) should be arrested:

Leaving laws in place creates another layer of protection for victims. The laws enable police to investigate these crimes and intercede. Sometimes taking a girl into custody allows her to be separated from her pimp long enough to get her help.

Concerned Women of America is a biased group, quite conservative and Christian, but have a good point. Child prostitution needs to be illegal. Duh. The liberal argument is, why prosecute a child, but the fact is, the under age victim rarely gets prosecuted. They get arrested, taken away from their pimp, or whatever abuser, and can get help. When it is legal, it can be ignored. Law enforcement can't intervene, only report it... to the corrupt child protection services in the government. Wtf.

It's the same thing we saw recently in California; underage prostitution was decriminalized, defenders claimed, "It's wrong to criminalize victims," critics pointed out that a child being abused in this manner is much less likely to get help if it's legal. They are instructed to tell LE they are doing it by choice. They are afraid to go to LE on their own, so arresting them is a good way to pull them out of their situation. Not to mention that, shouldn't it be illegal, fucking duh!?

The Democrats, and especially the Clintons, have a history of pushing laws to decriminalize child sex abuse. Here's a WSJ article from 2000, The Clintons Shrug At Sex Trafficking. Nancy Pelosi tried to push a bill decriminalizing sex trafficking in San Francisco, Preposition K- @quantokitty did a good post on it here- https://voat.co/v/pizzagate/1507948. And under president Bill Clinton, The Victims of Trafficking and Violence Protection Act of 2000, which required victims to aid in prosecuting their trafficker (which victims don't want to do...)

There have been a lot of shady trafficking laws. Good rabbit hole if you want to see who's connected to them. Bad thing is, they write these laws to look good on the surface. But, I think Sessions sees right through it.