The man, now in his 40s, said James Braid was a 'father figure' who had total control over him.
The English and drama teacher is accused of abusing four boys from Bay House School in Gosport, between 1982 and 2002.
Braid, who retired last year, is alleged to have invited the pupils, all under 16, to his home as well as taking them on trips to the seaside.
A jury at Portsmouth Crown Court was yesterday shown a video of the police interview given by one of his alleged victims.
The man, who cannot be named for legal reasons, said: 'I hadn't had a father so this man was the nearest I got.
'He has controlled me the whole of my life, who I can see, what I can do, how I can do it, it's all about this control.
'This man picked me up and moulded me into what he wanted.
'It's all about all this control he has had all these years and the effect it's had on me over all the years.'
He agreed to give evidence against Braid after the police contacted him as part of their investigation into allegations made by another man.
He said: 'What I would like him to do is admit to everything, admit to sexually assaulting me, admit to sexually assaulting any other person. Is he going to do it? No.
'I don't understand why he did it. I just feel very angry because what he has done to me and the effect it has had on me, still now, and the fact that he has obviously done it to others, how many I don't know.
'So I feel very angry about it. Yes it's happened to me, I don't want it to happen to anyone else. It's got to stop. I feel ashamed, I feel disgusted.'
Braid, 58, denies seven charges of indecent assault, one of rape and one other sexual offence.
(Proceeding)
BLACKMAIL CLAIMThe jury has been told that one of the alleged victims will be giving evidence from police custody after he was jailed for blackmailing James Braid.
Prosecutor Katherine Lumsdon said the man, now in his 20s, was jailed for two years at Portsmouth Crown Court earlier this year.
He blackmailed Braid after the teacher was cleared of a separate allegation of sexual abuse in 1998.
He wrote to him in 2007 saying he would go to the police unless Braid paid him £5,000, which he did.
He then demanded another £3,000 which Braid paid up. Braid said he agreed to pay because, having been acquitted once, he could not face another investigation into 'false allegations'.
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