Well.
I took one for science one time. I can tell you what happened.
I was standing by my kitchen island eating my raisin bran flakes with exactly 1/2 cup of skim milk.
In some weird coincidence a moth flitted around the hanging pendant light. Two Siamese cats decided it would be fun to jump up on the island and up to the light. There-by causing me to jump.
In a physics related confabulation, my bowl released from my grip. Went up about 2 feet and crashed down to the granite countertop. Smashing into a million shards.
I promptly noticed milk/flakes in my face, hair and shirt. No shards of glass.
The pressure was 100% released.
Except raisins were on the floor with the shards of glass. I presume their weight or maybe stickiness kept them with the bowl.
At about 3 minutes later the pressure was released on my mouth. And curse words emitted. Again 100%.
My conclusion: the liquid will fly out into your face. Wear eye protection.
And don’t eat cereal with cats stalking the room for flying insects.