opportunism

Santa Claus

is never casting one's bread upon the waters unless one is sure the tide is coming in.

An opportunist never casts his bread upon the waters unless he is sure the tide is coming in.

is never doing anyone any harm unless he can do himself some good.

An opportunist never does anyone any harm unless he can do himself some good.

is one who never goes back on a friend as long as he can use him to advantage.

An opportunist never goes back on a friend as long as he can use him to advantage.