Roborovski hamster question?

I am getting a robo hamster tonight and I wanted to know if it is ok just to get one? I will ask my dad if i can get two, and that i would pay for the extra one because i heard that they are really social and need a play mate but i didnt know if that was true? if so...what should i do? idk how to convince my dad to let me get two...if i need two could i have some reasons of how to convince my dad to get two? thanks :)