NTA

They thought they were very smart, tricking you into being their friend so they could get free trips out of you, and they weren't joking--they genuinely don't like you, and just see you as a means to an end for their amusement.

And no, you didn't go too far telling your husband. This is what spouses do, you talk to each other about shit, y'know?

They're all just upset they got caught, and even worse, now they have to explain to their kids that they can't go on the trip anymore.

They're going to spin it into you being an awful person somehow, too. You're better off without these awful people in your life. Pretending to be your friend and then using you for shit only to mock you and your son behind your back, and then insult you because they got caught? These aren't people you should be worrying about anymore, they are not worth your time.