Al, you nailed it. It was unconditional grooming.
Toby, I think getting Lee to book a hotel room is a start, he will probably not want to leave once he is in the field so good plan.
Clair,
Option 1, Book a Hotel Room but pack a tent (just for your daytime needs (Nudge nudge wink wink)), cancel the Hotel, make a fuss when you turn up to check in and they say there is no booking. Then say in a meaningful way "Oh well, at least we brought the tent" head back to the field.
Option 2, Drug him like BA Baraccus (You aint gettin' me in no tent fool!"