A teenager was seen dragging his girlfriend about then hoisting her into the air by her waist.
Brandon Gerrard, 18, of Bramley Avenue, Fleetwood, pleaded guilty to assault and was bailed for pre-sentence reports by Blackpool magistrates.
Adrian Hollamby, prosecuting, said a police officer saw Gerrard by West View roundabout, Fleetwood on July 6 in the early hours of the morning.
Gerrard was dragging his partner, then lifted her up.
Leisa Splaine, defending, said the couple met unexpectedly on a night out and had a row.
The girlfriend had made no complaint to the police.