Ha! Sometimes, they are, Tien. Sébastien is not a cuddly cat like Tango, who wants to be near Ben or me nearly all the time. Sébastien is independent and enjoys his solitude except when HE wants company. Then, he is relentless in efforts to gain attention from Ben and me or from Tango.
We adopted Sébastien because Tango was by nature a lazy cat. As he put on extra pounds, we new a companion was needed. Sébastien definitely filled that requirement. He can allow only so much of Tango's sleeping before he challenges him to a play-fight.
They are an interesting pair - complete opposites in personalities and interests - but still, like loving brothers.