Wylie felt really bad when we first got Marcel...and I felt so bad for Wylie

. He became very needy, clingy, and insecure...and I just let him have his feelings, held him, reassured him. If giving treats, we always gave Wylie his first - to let him keep his "alpha" position. He really wanted nothing to do w/ Marcel at first.
Now, they are best buds. Marcel is the *consummate* little brother and is totally happy w/ that role - he shadows and worships Wylie and just thinks he's the coolest.
I'd say Wylie started "opening up" to Marcel within maybe 3 weeks or so? It can take a little while, but they'll be okay!