A young male shoplifter was spotted putting yellow knickers in his pocket before leaving a Lincoln store, a court heard.
City magistrates were told that a security officer at Primark saw the man with a female. They both huddled together and the defendant selected the item before pocketing it.
Jim Clare, prosecuting, said he began to run when the officer tried to stop him but he was soon restrained.
The 20 year-old from Lincoln admitted theft on June 27.
Roisin McCaffrey, representing, said he stole the pants for his girlfriend.
Magistrates fined him £50 and ordered him to pay a surcharge of £15.