Tumbling Rules Question

[Beandip]

This may be a very simple result but I cannot seem to find one through a search.

Question: When successfully tumbling through an enemy, do you have to end up in the opposite square?

The Ninja wanted to tumble through a medium sized enemy who was blocking the entrance to a room at his flank. The Ninja wanted to tumble through the enemy into the room, basically making a u-turn around the wall. As the DM, I ruled you have to end up in the square opposite the one you started. Did I rule correctly?

[BowStreetRunner]

Nope. "Tumble at one-half speed through an area occupied by an enemy (over, under, or around the opponent)..." If your movement passes through the square the enemy occupies, it's a DC 25 Tumble check. It doesn't matter where you come out, just that their square was included in your movement.
If your movement passes through multiple squares occupied by enemies, you must make separate checks for each and the DC goes up by +2 for each subsequent check.