I think they are mad because they know he's a player so they probably think he's fucking around like always and lied about being in a relationship since they found out by the lawyer telling them he was in a gay bar so they prob thought he was looking for random hookups or something. I'm sure they'll change their mind when they see that he's really serious about Grahm. (I hope)

I was really hoping they would be mad for him keeping secrets not cause he’s dating a guy ╥﹏╥ Just let my boys be happy in love!!!!! Regardless he’s going to cry happy tears when he sees the couple rings ♡(〃ω〃)♡