Green leopard puffer fish squirting?

[Puffer-girl]

I recently started a tank with one green leopard puffer and added a new one today. I was aware there was a high possibility of aggression so I've been watching them very closely. At first the fish kindof eyed eachother and laid next to eachother a few inches apart. After about 30 minutes the smaller of the two began chasing the bigger one and releasing strings of white stuff. I'm assuming trying to mate or make territory? I know it's pretty rare for puffers to mate in captivity so I was wondering what this was for sure. Thanks!