The odds of Tuffnut and Rapunzel's first meeting going smoothly would be an imprudent estimate. Rapunzel's sweet, naive personality would clash violently to Viking behavior and conduct. Tuffnut, being the perfect example of the Viking adolescent, would frighten the poor girl and would instigate a negative response, i.e. a frying pan upside the head. However, she may find his more innocent qualities endearing, even adorable, and learn to see past the gruff exterior.
Fanfic writers like to portray Tuffnut's behavior towards Rapunzel with heavy sentiment, his idiotic behavior a ploy to hide his more emotional, romantic side.