buddy-buddy
Overly or obnoxiously friendly with someone, often for personal gain. He's clearly buddy-buddy with the teacher now so that she'll relent and give him extra credit. The new guy needs to calm down and stop trying so hard to be buddy-buddy with us.
buddy-buddy
 (ˈbədiˈbədi) mod. friendly; too friendly.  Why is that guy so buddy-buddy with me?