Vortigaunt threesome?

Got half life 2 whilst it was free. I was playing through the route kanal level and was I the only one to notice the secret cutscene in the sewer?

That part where you slide down into the sewer. There was 2 vortigaunts f..u..c..k..i.n.g and splashing mud everywhere, one was saying "the vortigaunt feels good" and "the vortigaunt must f..u..c..k harder"

I started freaking out because I didn't realise half life had nsfw scenes, and plus my mom was in the room aswell, and of course it happened when my headphones disconnected

Then a third vortigaunt emerges from out of the mud and says "the freeman must join us". When I walked over there it started automatically playing another cutscene. Gordon took off his suit and got undressed and started thrusting the bottom vortigaunt, then all 3 of them started saying "the freeman excelerates at all tasks"

Wtf valve? Has anyone else seen this? Maybe I'm the first to discover it. It's in a secret passage behind some boxes in the sewer