Am I cruel for doing this???

[snakemanjayd]

More than likely that is what they meant.

If you play that whole "in the wild" card, people will tell you "they're not in the wild!".

Alright, I get that, but it's not like you are subjecting them to unusual or cruel behavior. It does happen in the wild, and it's natural and the snakes don't get hurt.
I think people have a strange idea of what cruelty is these days.
They personify everything too far...
Don't get me wrong, I love my animals too, but there is a line.

As for them not breeding for a while after that, that is a good practical reason for you not to do it as a breeder, if you intend to breed both of them.
But not an ethical reason.