Honestly whip out my cock and join you nothing wrong with a little mutual masturbation. I'd probably even ask if after we both make ourselves cum once if we wanna smash our genitals together till we both cum a second time or more.
Politely inform you that you're visible from my house. I'd assume you'd be mortified and end up pleasantly surprised when you weren't. I would probably then go home alone, completely oblivious to your flirtations until 2 years later when I kick myself for the rest of my life.