Enemy

as in

"I’m not the enemy."

Variations: "Why are you picking on me? ... What have I done wrong? ... Why don’t you look at yourself? ... I’m not the one making you miserable."

Be very careful or he’ll most certainly slip through the net with this argument. He appears ingenuous but is cleverly putting the pressure on you to find "a smoking gun". Some absolute proof that he is a cretin. A careless, ignorant buffoon. Or whatever flaw it is you are pointing out to him.

Something that would stand up in a court of law as contravening the basic rules of the land. But, since you aren’t accusing him of murder - hopefully (not yet, anyway) - perhaps not even of anything more serious than a failure to realise how wonderful you are, "smoking guns" are likely to be in short supply.

So you will have to be at your absolute sharpest to avoid being trapped into a familiar and frustrating game of Ping-Pong with the phrases "You said ... No, I didn’t ... I said ... No, that’s not what you said ..."

As in: "You said you didn’t want to meet on Friday" ... "No, I said I didn’t know what I was doing on Friday" ... "No, you said you might be busy on Friday" ... "I said I hadn’t made any plans for Friday" ... etc etc ....

Sometimes he might actually be innocent of the charge and his defence actually genuine. Perhaps he didn’t set out to hurt you. Even so, he almost certainly could have handled the situation better, couldn’t he? Used a little proactive sweetness to reassure you. A few flowers and a definite date for dinner the following week.

Perhaps he isn’t Public Enemy No. One. But neither has he been behaving like Romeo. And whoever said you wanted to go out with someone whose best quality was that they were "not guilty" anyway?