Erza

As Natsu/Juvia desperately hobbled off to the unisex bathroom, he/she was stopped by Erza, wearing a white shirt and a blue skirt

"Hey Juvia, where are you going?" Erza asked.

The very sound of Erza's voice was like ice in Natsu/Juvia's veins. If his/her childhood tormentor had learned that Natsu was now in Juvia's body, she'd think he/she was a pervert and beat him/her senselessly. It shocked Natsu/Juvia so much that he/she released a little bit of his/her pee into his/her panties.

He/She was so scared, he/she couldn't even move from his/her spot and just stood there with a shocked expression on his/her face. Unfortunately, the need to pee was unbearable, so Natsu/Juvia began to shuffle uncomfortably in place to keep dry.

This did not go unnoticed by Erza, who at first was oblivious to Natsu/Juvia's plight. However, she noticed several empty mugs of drink around where she saw Natsu/Juvia leave. It wasn't long before Erza made the connection and quickly grabbed Natsu/Juvia's hand and quickly ran to the closest ladies room.

"ERZA, WHAT ARE YOU DOING?!"Natsu/Juvia cried out as he/she was being dragged against his/her will.

"A lady needs to relieve herself in a proper toilet. Even with your great need, it would bring dishonor to all women if I let you use an unsanitary restroom!" Erza replied almost yelling.

"SAY WHAT?!" Natsu/Juvia cried incredulously.

"Your bladder is on the verge of bursting and it would bring great shame to Fairy Tail if you wet yourself. That's why we're getting you to the closest ladies room." Erza said almost with pride.

Natsu/Juvia wanted to disagree, but his/her bladder's need was too great for him.her to argue. As they made their way to the ladies room...