Back Ground - Very long time friend of mine & DHs - he does have his good qualities, but can also be a bit of a knob at times, considers himself "highly intellectual" & can as a result be prone to looking down his nose at others as a result, my DH & many friends included
. He does tend to hang around with younger people these days & plays the part of the "troubled creative writer" to a tee - most of his old friends put this down to insecurity & also that he can get away with it amongst a younger, less worldly wise crowd, but we all do still love to see him, even if we don't agree with his scrounging, pseudo intellectual life style - apparently he's too intelligent for normal work, lost more jobs than you can count & even when he has been pushed into studying something he would be great at, such as teaching, he soon finds a reason to duck out of it. Generally we don't see much of him any more, but despite his faults we all (wider group) do love to see him when we do - this week was one of those occasions - a big get together for another old friends birthday.
After we left, several of us headed to a local pub to meet up with others - this friend comes too - telling us he's meeting a woman later at another pub, but stressing about not knowing where this other pub is, so gets woman to meet him at same pub we are all in - others leave , so just us & DD left (afternoon)- he's always skint & prone to scrounging beer, but as he didn't ask DH to buy him a drink this time, but as always only had enough for 1 drink - DH bought him a pint when he went to the bar - because he was enjoying his company, knew he was skint & wanted too.
All fine - except DH is very tall & can see above a partition the rest of us can't - he sees the woman friend is to meet walking along street towards the pub door - she's on her phone - friend checks his phone - gets up - grabs full pint DH has just bought for him & without saying a word - & heads outside to the tables out there - DH sees him sit out there with woman.
We were all, including DD 
at the blatant bad manners - DH was pretty angry as he's made a point of not buying friend drinks for a long while because of his world owes me attitude - he fully intended to tell friend what he thought of him at a later time, but we relaxed, ate, drank & then got up to leave - friend returns to our table at this point introduces us to Woman - who DH knew vaguely - makes a point of grabbing the table
DH did say he thought he'd redeemed himself a bit by at least coming back to say good bye & introduce us to his female friend - but it didn't get passed either DD of myself that he would see DH get up & put his jacket on & outside was now cold, so he was really only after the table - so I was still p'd off with him - so later tried to ring & ended up texting him how rude I thought he had behaved & that perhaps he should think about apologising to DH.
He replied that he had no clue what he had done wrong, didn't think he had done anything, but he apologised if he offended us in any way - I did speak with him & told him what he had done & he still didn't get how rude his behaviour was - I found myself having to put him straight that DH wasn't buying his company with the beer, but that a simple, "thank you, but will you excuse me I need to go & meet X outside" would have been enough.
He apologised, but STILL didn't get it - he's in his 50s, so IMHO should know better
AIBU ??
(migraine weather here, so please excuse typos etc