ulterior motive

I too had an ulterior motive: this was it, my chance to be alone with her.

"Maybe I do have a bit of an ulterior motive."

How could she have failed to see the ulterior motive?

But you'll have to take my word for it that I had no ulterior motive.

You needed to wonder what the ulterior motive was, what's in it for them.

Of course, there may be an ulterior motive at work, too.

Why couldn't she have been a man with some ulterior motive?

I hope there are no ulterior motives on either ones part!

I'm trying to think of what ulterior motives they might have to this.

"And we never do anything without at least one ulterior motive."