What is bassanios reservation about gratiano accompanying him to Belmont?

Bassanio is concerned that Gratiano's behavior may jeopardize his chances with Portia in Belmont. He worries that Gratiano's tendency to speak freely and act impulsively might create a negative impression, potentially undermining Bassanio's carefully planned courtship. Ultimately, Bassanio wants to present himself and his friends in the best light possible, fearing that Gratiano's lack of decorum could hinder his romantic aspirations.