The bodily version of a penis outline, when the abdominal bulge is in the shape of a penis. A good indicator is when it is possible to see the head of the penis in the bulge, but there are exceptions.

Related:

• abdominal_bulge
• neck_bulge
• pectoral_bulge

Not to be confused with

• penis_outline - When character's penis is very clearly visible through clothing.

This tag is currently used for multiple similar scenarios and might be worth splitting into the following to reduce ambiguity:

• "internal bulge details" when an abdominal_bulge is elastic on a small scale and shows details through the skin that would normally be impossible, such as penis veins
• "internal bulge distention" when an abdominal_bulge is elastic on a large scale and protrudes outward from the character in the shape of a penis