Sean said in today's Daily Record: "No matter where I am or what I am doing, Rory is on my heels.
"He has always provided healthy competition for me and there is no doubt his presence keeps me on my toes.
"Rory has produced a run of excellent performances for Glasgow in the Celtic League and there is no doubt he is a very good player.
"I have been luckier than him in terms of avoiding injuries over the past couple of years but have always been confident he would break into the pro game."
Sean is desperate to get a win against Ireland and erase the memory of last weekend's frustrating and controversial defeat in Paris.
He said: "It was so close and yet so far and we were completely gutted with the way it all panned out.
"Now we have to re-focus, build on the good bits from France and make sure we improve where it counts.
"The players feel that things are coming together and that we will achieve some very positive things over the next few weeks."
Sean admitted much of the feelgood factor was down to his Warriors team-mate Dan Parks, who kept the French on the back foot with his pinpoint positional kicking.
He said: "Parksy kept giving us great positions on the field and that was a major psychological boost for the whole team,knowing they were going forward a lot. Now we are excited at the prospect of stepping things up in front of our own crowd because they really spur us on."