Bubbling in the scrotum could be a loop of small bowel which has fallen in there (a type of inguinal hernia) and it bubbles because that segment is now confined/constricted. This needs to be checked by a doctor because if it is that, a strangulated bowel is a possible complication.
You can feel an inguinal hernia in the scrotum and testicles, but I'm not sure bubbling is a symptom of that -
https://www.healthline.com/health/inguinal-hernia#symptoms
You should absolutely get this checked out. The only way to get it diagnosed is by a doctor examining you, as Pax says. Let us know what happens.
Hernias are felt in he abdominal and groin area, not in the testicles, but other than that, nobody can really diagnose you without examining you.