As a straight guy, erect cocks are more attractive than boobs.
Everybody knows this. Cocks are the most attractive things humans have. They are smooth, they are not confusing in how they work (looking at you vaginas) and they are good sources of pleasure.
From a shape language theory perspective, cocks are more attractive. They have a natural curve, a natural line of motion, and the cock head has naturally contrasting shapes, the shaft being a curved rectangle and the head being more triangular. The roundness of boobs communicates cuteness or comfortablility whereas the penis has a square and triangle shape, which communicates trustability but the triangle presents an edge, so perhaps the penis is not all it seems, which interests people.
Sometimes, I just look at gay porn so I can admire the dicks. Of course that’s entirely from a purely shape language theory perspective lol.