Most Helpful Guy
Tell him you don't want to see him anymore and he's not allowed to park at your house anymore
Most Helpful Girl
I had an equally awkward situation, I broke up with my ex but we were living in the same 5 person dorm in college, we shared a living room and kitchen and bathroom, I couldn't not run into him afterwards. It was awkward at first, but after some time we got used to it and became friends again. I've since taken trips with him and some other friends and it didn't feel awkward at all. I think if you're friends, then walking back should be fine. It might feel a tad awkward in the beginning, but I think as long as you keep the conversation to neutral topics, don't stand too close or hold hands or borrow his jacket or anything, then it's fine.