Donahue walked free from Lincoln Crown Court after a jury cleared him of sexual assault and a second charge of causing a person to engage in sexual activity.
The jury took just an hour to return both not guilty verdicts.
Giving evidence, Donahue insisted the touching had occurred with the full consent of the younger man.
Donahue also denied that a further sexual act alleged by the prosecution happened at all.
The jury were told Donahue had agreed to pay the younger man £20 to practice giving a massage.
It was alleged the younger man, who suffers from learning disabilities, repeatedly told Donahue “no” as the massage progressed.
But giving evidence Donahue insisted: “At no point during the massage did he request me to stop.
“If he had done I would have stopped straight away.”
Donahue told the jury it was the younger man who initiated the sexual touching after he noticed him smiling during the massage.
Under cross examination Donahue said his shared interests with the younger man were watching the TV series Top Gear and playing on his Xbox.
The jury heard police became involved after the younger man’s mother discovered text messages between her son and Donahue in December 2015.
As a result the alleged victim was interviewed by police in March 2016.
When Donahue was questioned by police in April 2016 he accepted engaging in sexual touching but insisted it was consensual and instigated by the younger man.
Donahue, of Chapel Hill caravan park, denied a single charge of sexual assault between September 1 and December 20, 2015.
He also denied a second charge of causing a person to engage in sexual activity without consent between the same dates.
The Lincolnite welcomes your views. All comments are reactively-moderated and must obey the house rules. Please stay on topic and be respectful of other readers.
A Woodhall Spa man who allowed his cottage to be used for storing cannabis worth up to £140,000 was spared jail after a court heard he was not involved in the drugs trade.
Sonny Gillespie, 31, was sentenced to 15 months imprisonment suspended for 18 months after Lincoln Crown Court heard he was taken advantage of by a man called “Ron” who sometimes stayed at his property.