"I don't bring it up with him," the former Miss Ireland told the Herald ahead of Leinster's must-win Heineken Cup game at Exeter this weekend.
"He gets enough of that in the run-up to the match.
"Beforehand he has to talk about it, and after the match there is always analysis and everyone is asking him questions about how he played."
In fact, Holly says she's one of the few people in Cian's life who is not obsessed with rugby.
"I'm the one person who doesn't ask him. And I think that's probably a good thing.
"Cian leaves work 'at the office'. He never gives away what he's thinking about the match before or afterwards."
And Holly likes to forget about the trials and tribulations of modelling when she's hanging out with Cian and his dog Ted.
"I wouldn't talk to him about work that much either. We're both bored talking about it by the time we get home."
Instead of discussing their respective careers, health enthusiasts Holly and Cian prefer to stay in and watch movies.
As a model and a top athlete, Holly says that their healthy lifestyle is one of the reasons their relationship works so well.
"We can't go out and drink and eat loads of takeaway food because of our jobs. So we just cook healthy food and watch movies by the fire."
Holly and Cian started dating over a year ago after meeting at a protest over the Clontarf flood wall.
And Holly says the couple may start training together.
"We don't train together yet but Cian's just bought loads of training stuff for his house. He got loads of weights. We will probably start training together at some stage but I think we may just end up laughing."