The 'Charlie St. Cloud' actor is presently sporting new facial hair, but says it hasn't been such a big hit with girlfriend Vanessa, as he's always scratching her face.
When asked about his beard at the premiere of 'Charlie St. Cloud' in London's Leicester Square last night (16.09.10), Zac said: "Well Vanessa finds it very itchy when I kiss her."
Modest Zac, 22, also admitted he doesn't feel his facial fuzz quite matches up to that grown by 'Twilight' heartthrob Robert Pattinson, who recently cultivated a more rugged look ahead of taking a road trip across the US.
When asked whose mane was thicker, Zac told BANG Showbiz: "Probably Rob's."
Zac also told of his desire to work alongside more British actors, saying he'd sign up to star alongside "anyone from RocknRolla" - Guy Ritchie's 2008 gangster film featuring Gerard Butler, Thandie Newton, Tom Wilkinson and Tom Hardy - in a heartbeat.
Augustus Prew - Zac's co-star in 'Charlie St. Cloud'- said he got the opportunity to spend some time with the former 'High School Musical' actor and Vanessa when making the film in Canada, and they appeared very much in love.
He said: "We were up filming in Vancouver, and Vanessa was also in British Columbia shooting 'Sucker Punch', so she came over and my girlfriend was there too, and we all hung out.
"Zac and Vanessa are the sweetest couple, they are so in love."
'Charlie St. Cloud' is released across Europe at the beginning of October.
Tom Meighan is a great actorZac Efron Says ‘Charlie St. Cloud’ Is Not ‘Sappy’