I'm trying to have a friendship with him but he seems conflicted, any advice?

This guy has liked me for a while (just acts strange sometimes like imagine when your crush walks by and you try to act natural- it's very unnatural and obvious I think I hear alarm bells whenever he sees me and his behaviour quickly shifts) after I noticed he might like me, I started liking him a lot but we only see each other in a public space so our conversations are limited and I'm starting to think he's married or at least committed to someone else. Same guy as my last post, he is older and we have talked casually and he's told me about his kid but never mentions if he's with his kids mother, he has never said "my wife" or "girlfriend" or "partner" he just says "at home..." My gut says he's with someone because if he wasn't he wouldn't act so conflicted when he's around me - up and down on and off friend to stranger. He's never just normal with me, he's either excited to talk to me or actively avoiding any contact with me. I feel like he's upset by the situation and I am too. Sometimes when I go to speak to him, he tenses up and wont make eye contact and will hardly make a sound and tries to shuffle away from me so obviously that's a big rejection there. Yes I like him but all I'm trying to do is be friends, I don't have many friends and definitely no male friends, I'm not eager to date either but I am romantic at heart. I just want us to get to know each other because I've already seen so many similarities between us but he makes me feel like that's somehow inappropriate..? I don't come on strong or flirt either just friendly and ask questions about him. There is this other woman who is often around us too (public space) she likes him but she is very obvious about it giving him bedroom eyes and trying to be near him and I saw he would always turn his back to her, never talk to her and if she said hello he would give a quick hello back in an stern way. If he is like this because he is with someone, that just makes me like him even more because a loyal person is my type. Im usually a pesimist so believe me I have overanalyzed how he is with everyone and he acts towards me like there is feeling there, soft spoken, attentive listener, laughs at my dumb jokes, stands close to me and looks into my eyes with his sparkling eyes, but thats on the days he is engaging with me, other days he has his guard way up and he keeps going back and forth between the two. Any advice?