After what had happened with Utron, all Tony wanted -- and did, was to disappear for a moment and forget about it all. But that didn't happen the way he would have wanted; because Fury so-nicely reminded him as his still post of consultant at S.H.I.E.L.D.
So now, Tony was stuck between wanting to do something for Sokovia and doing whatever Fury wanted him to do -- plus, he was mourning his relationship with Potts (the poor woman had broke up with him, deciding the danger around him was too much for her).
So yes, Tony was practically out of his damn mind; that was, until you arrived. All he had heard (or rather, snooped around) about you was that you weren't really friendly. Not especially a good person. Tried to exterminate the Earth a few times. Weapon dealer. The kind of thing you could see at the S.H.I.E.L.D's quarters; it wasn't unusual.
The unusual thing was for Tony to feel attracted to you -- to feel a spark that he couldn't deny nor identify. It was maybe the sarcasm in your voice, the smirk on your face when you saw him, the unapologetic manners you had. You were real, you were something else.
But he was a hero (he hoped), he was a member of the Avengers -- how could he be into you if you were everything he was trying to fight? So Tony started to idealize you, trying to forget all you had done in the past, acted like it was long gone. It wasn't, and you reminded him every day he was around.
How bad do you want me? he remember hearing you say, once. A way to taunt him for his thoughts, for what he was trying to do -- because you weren't his ideal, you weren't a good person.
"You're right, this is insane." he ended up replying, chuckling. "You're not especially the archetype of goodness and peace on Earth. Do you think I can explain why I'm just... attracted to you? That sounds like a fever dream." Tony said, trying to brush it away. "You're no good and I'm trying to picture you as such."