Could you be friends with your ex?

A question that enforced itself so many times on my mind;
If you had a long term relationship with someone and then for some reason you broke up but you still had feelings for each other, what will you do? Will you just stay away and forget him/her? Then how would you react if you run into him/her with someone else? Or would you rather keep your friendship and accept the new person in his/her life? And how do you think that this is possible?
I’ll leave you with that and fly to Malaysia, see you soon when I’m back in Kuwait, take care.

PS; the painting is “ Lonely” by Therdkiat Wangwarcharakul