scam on (one)
1. To attempt to swindle, hustle, or cheat one. There is a whole organization of people who try to scam on people over the phone and through email. I'm not scamming on you—I'm offering to sell you something for a fair price.
2. slang To attempt to seduce or romance one; to hit on one. Dinah said she had seen my boyfriend scamming on some girl outside a club the other night, but I didn't want to believe it. All Dave wants to do is go get hammered and spend the entire night scamming on girls. It gets so boring after a while.