To inflict oral sex on a partner voraciously. A partner, for a
normal blowjob,
will go up and down, but when your partner "swings that neck", it involves a wide range of motion for suckage to occur.
example: a
fast, almost violent, circular or triangular motion.
Swing That Neck: a vicious, fast, and movement filled blowjob, where the partner sucking
will go ape shit on the
dick.
"She didn't just suck it man, she swung that neck. It was
crazy. "