Crush on childhood friend

I have recently been making an active effort to see an old group of friends from school a lot more, we're now in our 30s. When meeting up with this group, I have found myself drawn to one particular old friend who I have known since we were 5. When we were 16, we were both incredibly lonely and to some extent became each other's entire support network. I know now that I was horribly depressed and dealing with undiagnosed autism and ADHD. I was a train wreck at that time and he kept me alive. I suspect he is also autistic and was depressed but he's never confirmed that, I just recognise certain similarities. We would walk around our neighborhood talking most evenings and were inseparable. For a lot of that time (age 16-18) was aware that he had a crush on me but I did not feel the same, I just ignored it and continued to keep him as my emotional support because I could only talk to him and he stayed because he could only talk to me. Something I occasionally still feel guilty over. We went out separate ways for university and moved past that awkward phase, dating other people. I am in an 14 year relationship with my partner. He dated another friend for a few years at university but has been struggling to find someone since. When we have these friend meetups, he has increasingly been finding me on my own, staying up late to drink with me (I don't sleep much) or following me out when I go for a cigarette. This often turns into a bit of a therapy session where I comfort him and tell him that he will find someone to be with eventually. These conversations have become increasingly intense, going far beyond dating advice, getting deep about fear and anger and other things. It is clear to me he is really struggling with his mental health. But, through these chats we have also connected and chatted about a lot of other lighter things and it's reminded me how similar we are and how easy and comfortable it is to be around him. This has got me feeling back in teenager brain and my concern and care for him seems to have turned into a bit of a crush. I don't want to feel like this. I have a partner who I love, and do not want to leave for him. He is in a very vulnerable place and it would not be appropriate at all for me to tell him what I feel right now as I have no intention to uproot my life and move halfway across the country to our home town to be with him. Also he is still hung up on his previous relationship so he does not feel the same anyway. I want to be there for him but ultimately I am trying to suggest he gets some therapy to deal with his mental health and I have mentioned that he may want to look into an autism diagnosis, since he struggles a lot with stuff I recognise in myself and that I have worked on a lot over the years. He has outright told me he does not have any other friends he can be emotionally open with and I have been speaking to him regularly providing support and it keeps causing this uncomfortable crush to grow. I know realistically I need to put space between us for as long as it takes to deal with my emotions, but I encouraged him to open up originally before I was feeling like this and I think that cutting ties bluntly would cause him to spiral.

Well, have you thought about the truth, as in, "Bill, I really care about you but I'm honestly not qualified to help you the way you need. Have you asked your doctor for the name of a therapist?" Whether he has other friends or not they wouldn't be qualified to help him either. This is a job for a professional. I can't think of *any* circumstance where it WOULD be appropriate to tell someone you have a crush on him/her, unless BOTH of you are in a position to pursue a relatonship. On a practical level, I suppose you can set a timer when you sit down to talk/message/text to him, 'have an appointment you have to go to,' and have a picture of your partner in front of you while you talk? When this happened to me I arranged my life not to be alone with the person I was crushing on. Trying to maintain a friendship with my crush was a complete failure. You have a bit of a break here because physically, you're not close to this man. Geed luck, and good for you for recognizing what has happened.

You're about - what - thirty-five? There's another possibility: It may simply be a case of: he's (and I don't mean this nastily) being a bit of a baby and you're ripe for a baby so - You have this irresisible urge to mother - starving baby responds strongly - mum's bond deepens (and repeat). ?