Sea Hare blowing blue bubble...?

[Pier Pressure]

So my newly aquired sea hare is out at the front of the tank and it seems to be spewing a blue bubbly thing full of air. We are taking pictures/video with our new camera but until we learn how to post this description is the best I can do - it has something coming out of its mouth that is about half its size, blue and hollow (like a soap bubble) and has some pink looking parts involved at the outer rim of the bubble. Anyone know what is going on?