I need advice on a home situation with my new puppy PLEASE PLEASE?

I had just gotten a new puppy at a town picnic..... 2 month black lab... i live with my bro his gf and my bf they all thaught it was a good idea to get so we got him. i didnt think we could handel it they already have a teacup chiwawa and he is 7 months and isnt even potty trained. so at first it was the house dog. now its mine. only when it comes to taking care of it.. i named him toki..(from dethklock) . my bro and his gf doenst like it they call him toby.. now after a little over a week they dont like him cuz he plays too ruff with their dog.. (tito) tho... tito wont stop following toki around... toki is clumsyand cant get on the couch but tito will get on the floor, play and then cry out.. if you pull tito away he growls at you and jumps back to toki... its not my fault tito likes the dog but hurts when he plays he can easily get away from toki but he doesnt want to and now they are mad at me because i have to go to work and wont be ther to take and they want me to get rid of him