A repeat sex offender has avoided prison for a third time after a judge “took a big risk” to let him walk free.

Justin Willis, 19, had twice been given suspended prison sentences for sexual offences involving women in a club and on a train.

His latest indecent exposure on the 281 bus breached a 50-week suspended sentence handed down at Blackfriars Crown Court last May, after Willis ejaculated on a woman’s coat on a train from Clapham Junction.

Less than a month later he sexually assaulted another woman in a nightclub, for which he was given another suspended sentence, of 15 months, in January this year.

Suspended sentences mean a criminal is given a chance to stay out of trouble, with the threat of a prison stretch if they re-offend.

He was told he had avoided prison when he was sentenced at Kingston Crown Court on Wednesday to 10 months in prison, suspended for two years.

Judge Fergus Mitchell told Willis: “I am not sentencing you to prison today, and the reason is that it is felt that there is some progress being made here.

“It is an incentive not to behave in the way that you have been behaving. There is something there that you have got to suppress – society will not tolerate it. The law takes a pretty dim view of it.

“I am giving you all the credit that I can. I do not want to see you again. You know what will happen to you.”

Judge Mitchell said to probation officers who said he was engaging with them: “I feel like I am taking a big risk with this. I am responsible because I am not sending him down and keeping him off the streets.

“The defendant should express his gratitude to you.”

A spokeswoman for Rights of Women (RoW), a group which gives free legal advice to women, said: “Sentences of imprisonment may be appropriate to protect the public, particularly if someone is not engaging with other services designed to address their offending behaviour.”

Willis is subject to a two-year supervision order, and is banned from drinking alcohol or going into clubs or bars.

For more information about RoW’s free legal advice, visit rightsofwomen.org.uk.