What to say/do to my ex when I see him for the last time

I will try to keep this brief. I am seeing my ex (Male) soon to get the rest of my stuff. It has been almost a month since we broke up and we dated for a year and a half. There is a 7 year age gap and I am 23F. I know that I will sleep with him (I know I shouldn't but I know myself and I won't resist the urges). I want to know what I can do to make him feel crazy the way he did me? Is there anything I can say? Or a way I can fuck him so good he'll regret not having me?

For background, he texted his ex the entire time we dated, lied to me, made me feel like I would never be enough, and was a loser. He has no future, makes less money than I do, and is so lazy. Logically I know I dodged a bullet and should just take the win and move on, but my brain does not work that way. The only good part of the relationship was the sex...probably why I stayed to be honest.

I have so many urges to ruin his life but have resited so far. I want to go through his phone to know if he is talking to someone new when I go to get my stuff and scream and lose my shit...but I know it will not change anyhting. We are still friends online and he still texts me everyday, but I have not figured out his motive. He had texted once to meet up for sex but I did not see the message until the next morning so I assume that is why he's kept contact?

So my question is, when I see him and fuck him, what can I do during and after to make it drive him insane? If more details are needed to help me I can make an edit and add more. In terms of sex, I know what he likes, but what can I say during it to make it replay in his head?

I know some of you are going to tell me to just get my stuff and leave and I wish I was capable of doing that...I am open to slowly making him crazy but nothing where he would know it was me.

What should I do when I see him?