I agree with Chase about the last pic.
I also like to imagine this as a punishment for warriors or soldiers who don't get any kills on the battlefield. They are rounded up in pairs of similar height and it's their group leader's job to perform the ritual of strapping them together naked. While the heavy leather belt is still loosely fitted, the sharp points of the metal spike or double ended hunting knife are placed in the centre of their navels, then their leader slowly tightens the belt until their hard abs are touching. The braver of the two is considered to be the one who tightens his abs sufficiently to drive the point into his death partner first. It usually happens that the first one to get impaled on the point is also the first to squirt his hot death cum. The stronger hunk who manages to resist the sharp point then has to arch his back to support the body weight of his weakening death partner as his legs give way. This causes the belt to tighten further and sometimes makes the weapon suddenly jerk into the stronger man's gut. Or sometimes the weaker man's weight pulls them both onto the floor, forcing the pointed weapon up through the guts of the stronger man falling on top. They both then squirm together on the floor, enjoying their final explosions of cum.
I also like to imagine this as a punishment for warriors or soldiers who don't get any kills on the battlefield. They are rounded up in pairs of similar height and it's their group leader's job to perform the ritual of strapping them together naked. While the heavy leather belt is still loosely fitted, the sharp points of the metal spike or double ended hunting knife are placed in the centre of their navels, then their leader slowly tightens the belt until their hard abs are touching. The braver of the two is considered to be the one who tightens his abs sufficiently to drive the point into his death partner first. It usually happens that the first one to get impaled on the point is also the first to squirt his hot death cum. The stronger hunk who manages to resist the sharp point then has to arch his back to support the body weight of his weakening death partner as his legs give way. This causes the belt to tighten further and sometimes makes the weapon suddenly jerk into the stronger man's gut. Or sometimes the weaker man's weight pulls them both onto the floor, forcing the pointed weapon up through the guts of the stronger man falling on top. They both then squirm together on the floor, enjoying their final explosions of cum.