Brenock O'Connor once had a disgruntled stranger grab his thigh on a train and glare at him after his 'Game of Thrones' character killed Jon Snow.

The 18-year-old actor didn't realise ''how bad'' the reaction would be after his alter-ego Olly dealt the final blow to Kit Harington's character in season five of the HBO fantasy series, and he was left shocked when a mystery man manhandled him during his train trip home from school when he was just 16.

He exclusively told BANG Showbiz: ''I knew I was going to get a backlash, I just didn't realise how bad the backlash was going to be.

''But you've just got to realise that some people are going to get too invested, and that's what the show is great at.

''It gets people invested because it has reality in the fantasy and that's why it's so beautiful.

''I was walking through a train on my way from school. Because I was still in school, I was doing my GCSEs when I was doing that. This guy just grabbed my thigh on the train and I was like, 'What the hell are you doing, mate?'

''He just looked me in the eyes and went, 'Olly!'

''I was like, 'Alright, mate. Have a good day,' and then I belted down the train.''

While Jon later came back to life in the sixth series, Brenock didn't know that was the plan at the time, and he even kept his 'Game of Thrones' killing a secret from his sister.

He added: ''I didn't know he was going to come back to life at the time. No one knew. I think Kit and the writers knew and everyone else was completely in the dark.

''It was hard to keep the secrets but you just think of the pay-off at the end.

''My sister is Kit's biggest fan and she didn't know I killed him.

''She watched it in her house and I got a phone call saying, 'What the f**k have you done?'

''I was like, 'Sorry,' and she said, 'I'm not upset you did it, I'm just upset you didn't tell me,' and I was like, 'I was contracted and it was fun to keep it a secret from you.' ''

The 'Bromley Boys' actor can't wait to watch the final series of 'Game of Thrones', but hopes he doesn't find out any spoilers.

He said: ''I haven't asked Kit for any spoilers. They are sworn to secrecy, as I was when I was on it.

''I don't really want them anyway. I'm still a massive fan of the show, so I'm looking forward to the next season as much as anyone.

''The point of spoilers goes over my head, I don't get it.''

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