A Siamese On Trial !

Well i couldn't resist and we have on trial for a week a Siamese cat!
His name is Dillon, he's 20 months old and he's a red point Siamese. Basically it's a type of Siamesse that's been mixed with a Ginger Tom!
We've only had him 24 hours and things aren't going too bad. He finally ate and used the litter tray today...he must have been bursting ! Our cats Gypsy and Tramp are not impressed at all. Tramp wants to kill him and Gypsy hisses at him and has an expression on her face saying "How could you." We are having to keep Dillon in a separate room from them for a few days!
I hope it works out with him as Dillon is a lovely natured cat, a real fuss pot! But i will not keep him if it stresses out Gypsy and Tramp too much.
Fingers crossed X