Female Engineer

I work in the construction/engineering industry on a very major engineering project in London, in a fairly specialised role. Today I was having a conversation with two of my team engineers: one male, one female, with the male sitting in the middle of our line. I’m talking, and the female team member answered and I carried on speaking, when a man I had never seen before walked over with two other men in tow and cut straight across my conversation and said to XXXX, the male in the middle of our conversation, “Sorry XXXX, need to ask you something and thought I’d rescue you from a boring conversation” and smirked at me.
Jaw-droppingly rude and rendered me speechless for a second.
I stared at him for a couple of seconds and then replied with “Marvellous! Sexism in the workplace continues” – he went “Nonsense , it’s not that at all” and then carried on speaking to my engineer whilst completely ignoring me or apologising for is rudeness .
I subsequently find out this person is the replacement Project Field Engineer on this particular site.
Our future Interface Meetings are going to be fun!