Her sister always actually had a suspicion

Yeah, her sister always actually had a suspicion about the way she loved. It turned out she was right…

Her sister always actually had a suspicion
Only a suspicion is different from seeing it
By that I mean actually seeing it
The actual act
The activities, in reality 
The one-on-one action

Before she left, she said to the two:
"You are going to behave!"
The two girls promised to behave 
By mid-afternoon, they forgot that promise
In the backyard, clothes were taken off
In the backyard, a love game unfolded
In other words: intense sex in the backyard

That was all great and everything
Until the older sister opened the garden gate
Announced her homecoming with a cough
She said: "Is this your best behaviour?"
Her sister's friend said:
"Well, the behaviour may not be the best behaviour.
The feeling is the best feeling though!"

The eldest sister pondered and with a sigh she walked away
Her sister was just growing up too fast
"Have fun," she said, then added:
"When do you plan to do your coming out
in front of our parents? My advice is: just do it with clothes on!"