A man kicked his girlfriend in the face and attempted to strangle her.
Alan McTear lost his temper after the woman told him she had slept with someone else.
McTear, 21, of Lord Street, Blackpool, pleaded guilty to assault.
Pam Smith, prosecuting, told Blackpool magistrates the couple argued on Sunday after McTear told her he did not want two men she worked with at the flat for drinks.
McTear asked her if she had slept with someone else and she said yes.
He then kicked her on the left side of the face and then wrapped his arm round her throat.
After the attack the woman told him she had not slept with anyone else.
When interviewed McTear told police he had blacked out as he does when he gets angry.
Steven Townley, defending, said his client who had mental health problems, did not remember the incident.
McTear was bailed for pre-sentence reports and warned he may be jailed.