By Brian Farmer
Copyright bbc
Giving evidence, Sereaton said he got angry after Mr Singh-Gill offered him money for sex and grabbed him around the neck.
He wanted to stop Mr Singh-Gill doing “what he was doing”, the defendant told jurors.
Sereaton said he was “close” to the victim, never intended to harm him, and had stayed with his family for “a while” when he was younger.
Mr Christie said Sereaton had 19 convictions dating back to 2001 for crimes including robbery, burglary and drug supply.
He also had mental health problems, he explained.
Mr Singh-Gill, on the other hand, had a history of sex offending dating back to the early 1980s, Mr Christie added.
These included indecent assaults on males and females, and the prosecutor said he was placed on the sex offenders register in 2002.