Henry caught Claudia and Sean doing it on his bed, didn't understand what he saw but told Jimmy, who now doesn't want to sleep in his bed. Sean tried to talk about sex with Henry. And not to do it like Walt. But Sean's way backfired.
Sean talks to Henry about the birds and the bees, after he walked into him and Claudia having sex. Henry then tells everyone at school; Jimmy is found sleeping anywhere but his bed when he finds out Henry walked in on them having sex in his bed.