Friend flipped out on me because I didn’t offer to buy his lunch at an expensive burger place.

One of my (41f) closest friends (38m) moved out of state, and we hadn't seen each other probably in about 12 years, although we do still text regularly and speak occasionally. Yesterday I was out and about running some errands when I randomly get a phone call from him saying that he's in town and asking if I'd like to meet for lunch, and I agreed to meet him at Five Guys (his choice) in an hour. Now I had already eaten, so I just had a milkshake and we talked and caught up while he ate his meal. He said he was having a really rough time and his wife had kicked him out. So his mom offered to buy him a plane ticket home and he was going to be staying with her for a couple of months while he and his wife figured out what their next step was.

After lunch we were just kind of walking around the shopping center to get some exercise and chat a little more, when I was approached by a lady asking if we had any money. Friend said no, he was broke, and I said "I don't carry cash, but if you're hungry and I can buy you something to eat." She agreed and so I went into Panda and bought her two egg rolls and a side of white rice, then left her in the restaurant to collect her food and returned to my friend who was standing outside waiting for me. And he's looking all upset so I ask him what's wrong. Below is the conversation, probably not verbatim but as close as I can recall:

Friend (F): I can't believe you just did that.

Me (M): Well, I can't do it all the time or for everybody, but (my husband) found a $10 bill at the park yesterday so I figured I would pay it forward.

F: Oh, ok. So I open up to you, tell you about how broke I am and how much I'm struggling rn, and you don't even offer to pay for my lunch, but then you go and buy lunch for a total stranger?! Thanks, way to spit in my face.

M: I really don't know what to say to this. I mean, you are the one who wanted to eat out. I would have been happy to have you over for dinner and (my husband) would have put a couple of burgers on the grill for you.

F: Well I hadn't had 5 Guys in over a decade, so I just wanted to taste it again as a treat since there's one nearby. Sorry that's such an issue for you. I guess you don't think I deserve that?

M: Huh? It's not an issue for me at all; I don't care what or where you eat. You're the one getting mad at me!

F: You know what? Nvm because obviously you just don't get it.

And then he just jogged off toward his car. So I was just standing there, completely baffled. Guys, this is SOOOOO out of character for him! Or, at least it is with me. He's never asked me for money or anything before. Not even once. I mean, I've sent him money in the past (transferred him $30 as birthday present, for example), but he's never asked me for anything. I figured maybe he just lashed out because he's got a lot on his heart right now, so I sent a text to him today hoping to smooth things over. You can see the result. I haven't responded back to him because, well, I'm fucking off as he asked. And now my husband is all pissed off and ranting about how he should go to Friend's mom's house and kick his ass.

Does anyone have a clue what the heck might have happened here? Had I known that he was low on food money I would have been happy to feed him, but it wouldn't have been at Five Guys! Was my buying lunch for a homeless person at that moment insulting? I am just so confused, and if I'm being honest a little heartbroken at losing my friend over what seems to me like nothing.

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