How to deal with unwelcoming Teammates

[djdj_888]

I'm a relatively new team member and I had the luxury of having lots of friends already in the robotics program but, sadly not everyone has this luxury. Let me get to the point a new member recently joined the team and another relatively new team member is acting like a complete douche to the new member. One example was when the latter tried lying to the the former about a build meeting that's happening for our team on Saturday. I called him out on that and the latter said "I don't want him there." That really aggravated me and I decided to let our Team Lead Mentor know tomorrow and tell him to pair the two together during the Saturday build. How would you guys deal with a situation like that? Was it a good move or a bad move what I did?

Sorry if I posted this in the wrong section. Move the thread if I did it wrong.