Primo admits he will be 'up and down like a yo-yo' when the national anthems are played ahead of Italy's home game with Wales, although there will be a little bit more gusto going into Mae hen wlad fy Nhadau than Fratelli D'Italia - even though he doesn't know the words very well.
He may want the boys in blue to notch only their second championship victory, but Primo will be backing his eldest son Rob on what is expected to be his Six Nations debut.
'Whenever Italy play Wales in football, I always back Italy. Football is a religion in Italy and it would be hard not to support them,' admitted the 58-year-old Primo.
'But when it comes to rugby, I'll be backing Rob if he plays and Wales - even though they will be playing against my country.'
Primo came to Wales looking for work forty years ago and didn't expect to stay for a lifetime. He worked for some relatives in Pontypool, moved to Pontypridd and now owns the Busy Bee fish and chip shop in Merthyr.
He fell in love with a girl from Cardiff, Barbara, in 1968 and they married a few years later. Now, Wales is very much his home and their two sons, Rob and Peter, have both won the red jersey of Wales at Under 21 level.
But it could have been very different for Rob, who won his first full cap in South Africa last summer and has now developed into a stalwart of the Pontypridd and Welsh packs. For back in 2001, the Italian rugby authorities invited him to join their national squad with a view to playing for the Azzurri ahead of Wales.
'It was very nice for Italy to take notice of Rob, but when they asked him I think there was only ever going to be one answer. He was born in Wales and is Welsh through and through,' said Primo.
'It didn't bother me and now he is in line to play for Wales against Italy it shows he made the right decision. If someone had told me 10 or 12 years ago if my two sons would be playing international sport for Wales I don't think I would have believed them.
'I didn't know anything about rugby until Rob started playing at the age of 12. All I knew about was soccer and motor racing.
'Now I watched a few games I like the game, although I still don't really understand the laws. What I do know is that Rob is a very dedicated sportsman who plays it straight both on and off the field.
'He still lives at home with us, but whereas when he was a youngster he used to be popping into the shop for a bag of chips, now his diet is strictly organised and it is chicken, pasta and rice every day.
'We were thinking about going to Rome to watch the game, but we've decided to stay at home instead. My brother and three sisters all followed me to Wales from Bardi and they'll be coming round to the house to watch the game with us and have a few drinks.
'The name Sidoli in Bardi is a bit like Williams in Wales there are so many of us. They've run a few articles on Rob in the local papers in Bardi, but I don't know if his relatives in Italy will be supporting him on Saturday.
'We go back to Bardi for holidays once a year and in August it is like being back home in Wales there are so many people visiting their relatives. Rob and Peter enjoy meeting up with their Italian family, although I wish I had taught them both a bit more Italian down the years.
'Rob can understand a bit and that could come in handy in Rome next weekend.'
With five caps to his name, the 23-year-old Sidoli is developing into one of the central figures in Steve Hansen's Welsh team plans. But he could so easily have been lining up for John Kirwan's Italian side on Saturday.
'There was an offer on the table to play in Italy and join up with the international squad. Of course, it was tempting because to play international rugby is the pinnacle for any player,' said Sidoli.
'But it was never in my heart to turn my back on Wales as it has always been a dream of mine to slip on the red jersey.
'It was a complete shock when I was called up for the tour to South Africa last summer and it took a while for it to sink in.
'My rise in fortunes has been largely down to Pontypridd's success. People have stood up and noticed what is happening at Sardis Road and I have been lucky enough to have been noticed.
'It is all a dream come true. I am going to make sure I really savour the whole experience.'