Their barrister Mark Wyeth QC said: 'Mr Fry who is Spencer's partner was due as the new president of the Lterature Festival and was due that afternoon to give his inaugural address.
'They hit a large backlog of traffic and in a moment of indiscretion Mr Fry suggested to Spencer that he might like to get a move on.
'No other drivers were inconvenienced and he eventually did make it by a matter of a few minutes, in time for the festival.
'Mr Fry assumes all responsibility because it was his decision that made Spencer put his foot down.'
Fry, dressed in a green corduroy jacket, checked shirt and pink tie, watched in court as his future husband was handed his punishment.
Spencer was told by the magistrates: 'Your partner persuaded you to increase your speed so you were not late for an engagement.'
After the hearing, the newly engaged couple were ushered out of the co?urt building via a back entrance.
They then walked to Fry's £150,000 Bentley - which Spencer crashed yesterday in London - and left the small Welsh town.
Smiling Fry was in a jovial mood and signed autographs and posed for selfies inside the court building before the hearing.
And as the magistrates considered their decision he teased Spencer - telling him he was "probably facing a stretch in jail".
After the case he said the time since announcing their engagement has been "wonderful" and that they planned to tie the knot within the next year.
Speaking after the case Fry said: "It's been wonderful. We've not fixed a date and if I had I wouldn't tell you! But I can say it will be sometime within the next year or so.
"As is the way with these things it became public when we filled in the paperwork.
"It was probably a bit much to expect a quiet ceremony."
Earlier Mr Spencer's parents spoke about the upcoming wedding, saying they are 'over the moon' after the star revealed he will marry their son, who is 30 years his junior.
Robert and Miranda Spencer, from Southampton, admitted they were delighted about the couple's decision to wed after their whirlwind romance.
The couple were first seen together last November, but the pair are understood to have become serious over the summer.
Mr Spencer's parents have given them their blessing and Mr Fry said: 'I have met them and they are very nice'.
The pair could been seen engagement rings on their wedding fingers and Mr Fry added: 'They are very similar, both are made of Rhodium and are almost matching.'
The engagement came less than three years after he tried to kill himself during an unhappy spell in his life where he struggled to cope with fame, loneliness and the break-up of his previous relationship.
Mr Fry, who suffers from bipolar disorder, revealed that in 2012 he tried to kill himself with a cocktail of vodka and pills, and was only saved by a producer who discovered him.
Friends have credited the young stand-up comic, who is 30 years Fry's junior, with putting a smile back on the actor's face following a crippling battle with depression.
