Praise be to Allah.
It is not permissible for a woman to have a relationship with any man who is not her mahram, because of what these relationships lead to of haraam things such as looking, enjoying listening to the other’s voice, speaking softly, and becoming infatuated, and other things that are even worse and more abhorrent. This is one of the effects of haraam mixing which the righteous have always spoken out against and explained the dangers and evils that it involves.
For more information, please see the answer to question no. 84089.
We praise Allah, may He be exalted, for having enabled you to repent and for averting from you evil and sin.
As for the pictures that he has, if you think it most likely that he will return them to you without trying to bargain with you or delaying giving them back so that the relationship will last longer, then ask him for them, and return his pictures to him.
But if you are afraid that he will take advantage of your request to threaten you or try to bargain with you, or you think it most likely that he will never give them to you, then do not ask for them, and get rid of the pictures of him that you have, for it is not permissible for you to keep anything that will remind you of haraam actions or that may tempt you to go back to them.
You should beware of the tricks and schemes of the Shaytaan, and make sure that you thinking about the issue of the pictures is not because you want to speak to him again. If that is the case, then forget about the issue of the pictures, and put your trust in Allah, may He be exalted, for He is the Protector and is sufficient for His believing slaves.
We ask Allah, may He be exalted, to grant you His protection and to make you steadfast in obeying Him, and to ward off from you the schemes of the schemers.
And Allah knows best.