Didn't you say that she had a boy friend? If so prehaps you could let him know that she is is seeing her boss?
Or even better call head office and make a complaint about how you were sacked because your boss was seeing a member of staff, who you happened to ask out for a drink. She took offence...
Whatever you do, bend the truth when you go for your next job. I had an application form recently where someone but next reason for leaving last job.....
I failed my probation period.
Needless to say he did not get an interview.