I have two changing bags. [greedy]
For days out I have a huge Mylo changing bag from Mamas and Papas that I intend to reuse this time around. It fits perfectly in my Britax travel system, has lots of useful compartments and can handle my obsession with being over prepared.
Meanwhile, when I'm just popping out somewhere then I just use the free changing bag from Boots.
Moomin, I'd definitely get your OH to escalate! That sort of behaviour is completely unacceptable in any circumstances, but especially from a colleague in the workplace.
If the store managers aren't taking him seriously, then go higher up. Does he have a number or an email for head office? There will be a HR department and they will definitely have to take note and intervene.
In the meantime, maybe come up with some witty retorts designed to embarrass the guy and draw attention to what he's doing, to hopefully get backup from the others? "Can't find your own?" "Jealous?" "At least mine work." etc.
Two weeks to go until drop zone! Can't wait, starting to feel really heavy and uncomfortable now. I keep getting woken up with hip pain and my bladder is being squashed to the size of a thimble. Also, right now, feels like I have an octopus inside me. 
MW confirmed that DD2 is head down impatientlywaiting, but I feel movements and prods pretty much everywhere now. Between all the feet, knees, elbows and hands she seems to be able to reach pretty much everywhere! Got a mean headbutt as well. She spins round so that sometimes she's facing front and sometimes she's facing back.