Um, Amy? I agree that the LW's "single, older, male next-door neighbor" is kinda creepy—giving gifts to the LW's sons, asking them not to tell their parents about them—but it's a little unfair to invoke Jerry Sandusky:

I can certainly understand an older individual having young friends. But the red flag is that this neighbor has asked your sons to keep secrets from you. No responsible and respectful adult would ask young people to lie to or deceive others. You should be completely frank and honest with your sons. In the age of Jerry Sandusky and countless other stories of trusted adults "grooming" and then victimizing young people, if you "err" it should be on the side of transparency and honesty.

The LW should go to her sons and say, "You do realize he probably wants to get into your pants, right?" But however creepy the LW's neighbor is, Amy, he's not raping-little-boys-in-locker-rooms creepy criminal. And one adult lavishing gifts on another adult—even a younger adult—in the hopes of maybemaybemaybe getting into the younger adult's pants isn't an example of a "grooming behavior." Take it away, Hero Project:

GROOMING BEHAVIORS: A child sexual predator knows that in order to sexually abuse a child without fear of discovery, he/she must be able to condition the child not to tell another adult. The predator must also persuade other adults of his/her trustworthiness with children. This process is known as “grooming.”