The only person who seems to know who these kids and how they feel about Burt is... (do I have to state the obvious?)
...drumroll, please!...
Burt!
Now, I'm not calling him a liar (well, not yet, anyway) about the kids. But without independent verification, one can not take his statements at face value. (And that pertains to more than the kids)
You know all those stories you hear about some old fart keeping young kids locked up in the basement for years because "they love him"? Need I say more?
A clear conscience is usually a sign of a bad memory