Stevie Morley, from Dewsbury, watched from her window as her 16-year-old was set upon by the trio just before 9pm.
She says they struck the youngster over the head several times before one of the men bundled him into a car to continue the beating.
Rushing to her son’s aid along with a neighbour, Stevie’s son was released before the trio sped off. The 16-year-old was not seriously hurt but is said to have been severely shaken up by the incident.
The concerned mother said: “It’s just the worst thing you could imagine seeing. I looked out of the window and there they are, pushing him, laughing at him, punching him.
“My son is alright, but at the end of the day the fear is that if these people can do something like that to a 16-year-old boy outside his own home, what are they capable away from residential spaces, out on the streets?”
As well as her son, the attack has had a profound effect on Stevie, who suffers from a number of mental health conditions.
She said: “It’s terrifying. I just can’t believe it happened. I feel like I can’t go out, I can’t walk the dog. then I’m having to pep myself up to leave the house because I don’t feel comfortable there. It’s horrific.”
The attack comes just a few days after Stevie’s mental health support group, Take Ten, won a fundraising award to help set up a support group for teenagers and young people.
A West Yorkshire Police spokesperson said: “Police are continuing enquiries following an assault in Dewsbury on Friday evening.
“The incident took place between 8.20pm and 9.30pm on Friday September 14 after the victim, a 16-year-old boy, was assaulted in the street by three male suspects who got out of a car
“The victim was further assaulted by one suspect before the parties were broken up by bystanders, with the main aggressors leaving the scene. Anyone who has information about the assault is asked to contact Kirklees Police.”