I don't know; I'm a pretty disciplined guy with my money, but when it comes to food and eating out...
- At work, usually the senior person picks up the tap and it's expensed. I'm senior about half the time.
- At home, with family - wife, kids - I pay 100% of the time. If my oldest wants to, sometimes he picks up the tab, but usually it's me.
- With my close friends, we've been together for 35+ years; it all evens out in the end, IMO, even when it doesn't. I have friends that have short arms and long pockets, and it is what it is. I'm friends with them for other reasons.
- With "new friends", like DTF meetups, usually I will open a tab. Honestly, I'm not losing a friendship over the price of a beer or a sandwich. If no tab, I will throw cash in. I'm sorry, I'm not singling out anyone here, but I am NOT EVER figuring out my share to the penny; I will invariably overpay in those situations, but again, for me it's not a "cash transaction" like buying a CD or paying for an oil change. If I'm meeting up like that, it's supposed to be "fun" and that's for me the price of that fun.
And, not going to lie, I sort of like the feeling of picking up tabs. Not ego, like I'm a bigshot, but rather as a gesture of friendship. Like I'm sending the message that "I'm not letting $$ get in the way of our friendship" kind of thing.