Seriously? - I mean it isn't like leaning on the person is it.
When you lean on my chair....
I cannot turn around
I cannot move - you hold me hostage until you let go
You are in my personal space, making me uncomfortable
- just as if someone came and deliberately stood on your shoelaces, refusing to move and forcing you into stillness, taking away your freedom and imposing themselves into your personal space while leaving you powerless to step back to a comfortable distance.
Would you like this to be your normal? Do you really think this is okay?
In reality it's more than that.
If I relax back into my chair, you could tip the chair over backwards, injuring me, and I feel every movement you make - like someone kicking the back of your chair on the train. Plus extra pain with every movement.
Yes, there are times when leaning is OK - and those times can be roughly categorised as 'when closeness of relationship and/or specific situation means that if there was no wheelchair, there would still be leaning - a 2 way, mutually accepted lean. Like when spending quality time with the nephews and nieces.
But in any other situation - step away and don't stand on my shoelaces.