Because you're sweet on this dame here and if I can't get her no one will.

"I thought you were sweet on the woman from the first murder scene."

He was sweet on her himself, but Rita wouldn't give him the time of day.

Rather as though she were sweet on him herself and he'd turned her down.

"She has become sweet on a particular young man, and never would I take her from that."

Back in the old days, he'd been sweet on her.

He's sweet on her, that you can see easily enough.

"You're sweet on her and thought you could score some points."

Of course, I always knew as she was sweet on the doctor.

"Ever since she came here you've been sweet on her."