How do I stop the tension between him and I?

I'm 90% sure this older man is hiding his feelings for me. It's all in how he acts around me, looks at me, talks to me etc. I'm not confident but I struck up conversations with him to break the ice but it always felt like the ice needed constant breaking every time we saw each other. After awhile of casual brief talks, we shared some information about ourselves and he told me personal things so I felt like he trusted me somewhat. More time went by and he would be really interested and excited to see me and talk to me and other times he was super guarded and even sometimes would be harsh if I spoke to him so I would give him space and he would watch me waiting for me to approach him again. I eventually asked him why he acts this way and that I would like to be friends and I guess he felt cornered and didn't want to tell me how he felt because he was harsh with me again so I stopped all communication with him. It's been a long time since we last spoke but we see each other often and he's often paying a lot of attention to me (I'll look up and he's already looking at me, I'll move somewhere and his eyes follow etc.) Since I stopped talking to him, he has tried to get my attention numerous times by getting me to look at him and then he smiles at me but I never smiled back because I'm not ok with the way he handled things before. Him gaining my attention and sending a friendly smile didn't work in getting me to talk to him again so now it's a situation where there's a lot of tension. I try to act normal and feel normal but it's just so obvious we both feel tense around each other and avoiding the elephant in the room. I don't know what to do from here, I did and probably still have feelings for him but that falls second to me trying to be logical. As it stands it's just very tense between us and I know he feels it too (he'll keep watching me all the while acting like he's not watching me and being anxious and he just becomes really alert/on guard when I'm around.) How do I stop the tension?