The actor, who has played Blake Lively's love interest on television and now plays James Franco's in the movies, didn't mind comparing the two when it comes to their lip-locking styles.
How does Franco fare? "He was fine," Tveit told PEOPLE nonchalantly on Wednesday at the New York premiere of Howl, which costars Franco.
And how about Lively, whom Tveit romanced as Trip van de Bilt on Gossip Girl? "She was awesome," he replied enthusiastically. Better than Franco? "Yeah, sorry James," Tveit said with a smile. More of an electric charge with Lively? "Yes," Tveit admitted. "Definitely!"
Perhaps the scene with Franco was just unfamiliar territory – since it was the first time Tveit had kissed a man. How did Tveit prepare to shoot the scene? "I guess some breath mints," he says. "Make sure everyone's on the same page."
"Luckily it was the last day I worked on the movie, so it was easier," he says. "I'm wearing underwear, and he's wearing clothes."
For his part, Franco – who plays beat poet Allen Ginsberg in Howl and also kissed Sean Penn's character in Milk – told PEOPLE that doing same-sex love scenes isn't a big deal for him.
"I don't really think about it," he said. "I just do it."