My dad had always been a quiet man.
He wasn't the type to explain himself, and whenever someone questioned him, he usually laughed it off.
But after my stepsister came to stay with us, something about his behavior changed.
At first, nobody noticed.
He started buying her things she casually mentioned wanting. If she said she needed a new phone charger, somehow he'd already bought one before she even asked.
Then came the strange part.
Whenever she entered the room, Dad would suddenly stop whatever conversation he was having.
One evening, my stepmum noticed him quickly hiding a small gift bag behind his back.
"What is that?" she asked.
"Nothing," Dad replied.
"Nothing doesn't come in a gift bag."
He laughed and walked away.
My stepmum didn't laugh.
A few days later, Dad changed his usual routine.
He began dropping my stepsister off at school himself, even though there was a driver available.
Then one afternoon, my stepmum came home unexpectedly and found Dad waiting outside for my stepsister.
"Why are you here?" she asked.
Dad looked uncomfortable.
"I just came to pick her up."
"Since when?"
That question silenced him.
From that day, my stepmum started paying attention to everything.
The private jokes.
The sudden gifts.
The way Dad seemed overly protective whenever anyone criticized my stepsister.
None of it proved anything.
But together, they made my stepmum uneasy.
One night, she finally confronted him.
"I don't know what is going on between you two," she said. "But the way you're behaving is making me uncomfortable."
Dad immediately became defensive.
"You've misunderstood everything."
"Then explain it."
He couldn't.
At least, not immediately.
And that was when I realized something frightening:
Sometimes, you don't need evidence to create suspicion.
All it takes is a series of strange little things...
And my dad had been giving my stepmum plenty of them.