A best friend that is acting strange and seems to be hiding something from you.
Duder 1: "So, dude I'm moving in with my girlfriend in a couple months. I couldn't hang out on Saturday because we were looking at apartments."
Duder 2: "You son of a bitch! I knew something was going on. You were totally acting like a shady bff."
Duder 1: "Ha ha yeah dude sorry. I was going to tell you, I just didn't want you to get mad!"