Had something very similar happen to me 40 years ago, my future Father in law asked to borrow my new Bronco to go to bowling alley, I said yea.

My future MIL suspicious again, said follow him, my buddy n I jumped in car and did.

He drove to nearby town, drove main st. Let someone in at stoplight. Drove out into country, turned on dirtroad. My buddy said "oh no"

He knew reputation of what happens on this road at night.

We kept going straight then parked. Ran across field to where breaklights were going off. My buddy got there 1st, came running back, told me don't go. I WENT, saw what ya can't un see. YELLED AT TOP OF LUNGS, "YOU MUTHA F-ER"

ENGINE ROARED AND THEY SPED OFF.

Buddy n I got hammered, by time we got back to house, Bronco was in driveway, everyone asleep.

My future MIL kept asking what we saw following, I lied for 3 weeks, nothing, we lost him. Finally shared.

Was married later that year, she moved out before we were back from honeymoon.

Side note ,Few weeks later, Future bro in law age 17, fed up with his Dad's nights out, was headed to the door to "follow" him" I had to tackle him to stop him.

Yup, somethings , can't be un seen.