Look. I know you have a thing for him. You make it obvious every fucking time I see you. The thing is, you're in a long term relationship so I thought your flirting was harmless. Until you tell him you and your husband are in an open relationship.
He's too oblivious to know you're flirting with him or dropping hints. But guess what? I'm not. I know what you're doing and I'm fucking pissed. It's not that I think he'd touch you (never in a million years sweetie. He isn't attracted to you and he's faithful as well... Old Faithful.) it's that I don't want your skank paws all over him.
If you so much as touch his arm I will rip you apart. Stay the fuck away. I don't give a flying shit what you do with your own relationship but respect me and mine. Otherwise you're getting a fucking black eye (at least) for your trouble. Believe me. I've done worse things and you aren't shit to me.