Two thoughts as to possibilities, although maybe remote since I do not really know the situation:
- He is divorced, and had to split things with his wife, and is concerned then about another divorce should he marry you, meaning he has to split his split again - so he is leery of letting things get too serious since it could impact his retirement security.
- He does not believe that you really want to be together as man and wife - he thinks you like things to be kept at a distance and ‘hidden’. (Don’t rush off and do something rash with this man just to show him how serious you are!) After all, you’ve never complained - to him - when he keeps you ‘hidden’ in front of his friends, so what is he to think? Maybe he thinks you want to keep it secret, that you don’t want others to know because you are not serious enough about him.
The answer, before leaving him and regretting it later because you never asked him:
talk, FRANKLY, about it - ask him directly (instead of us) why he keeps you at a distance when around friends. Go from there: if he asks if that bothers you, be honest and tell him yes it does, and you thought you were more than that, and want it to be more than that.
In fact no matter what he says, or if he stares like a deer in the headlights, be sure to let him know you want it to be more than that.
If he says he does not, then ask if he is concerned about finances or just not sure about you. If it is the latter, he is not sure, than tell him you don’t want to see him too much anymore.
If he says he would like it to be more than that too, than you’ve got something - so then see how he acts with you in front of his friends etc - if he shows more affection in front of them, then maybe you got something there!
I would not let it go and always wonder, without directly bringing it to a head. Life is too short for that, and none of us are getting any younger.
If you want him, fight for him, give it your best shot, ask him directly these things. Only then will you know. It might hurt, or it might be one of the happiest moments of your life (and his, too). You’ll only know if you ask. Suck it up and go for it!
God bless you.