Geoffrey Johnston, who has taught at Fazakerley High School in Liverpool since 2004, was also accused of making fun of pupils and speaking to them about his "personal and sexual matters".
A General Teaching Council (GTC) panel heard he was suspended in 2008 for having "inappropriate" conversations with children and a forensic search of his laptop found he had used it for gambling and searching for sex toys.
According to the Times Educational Supplement, investigations into Mr Johnston began when three pupils told a senior teacher they felt "too uncomfortable" to go to his lessons.
The GTC panel said: "They stated that he made fun of pupils and when they became upset Mr Johnston claimed it was just ‘banter’. He also spoke to pupils about personal and sexual matters relating to his relationship."
In the same year Mr Johnston had called pupil A “a fat gay boy”, which the panel said was "demeaning and discriminatory".
It concluded: "His conduct fell below the standard expected of a registered teacher and the standards of propriety expected of the profession. Accordingly, he is guilty of unacceptable professional conduct."
Mr Johnston will have to complete training on safeguarding children before taking up another post.
Source: Pink News