You are with the Haitani Brothers, and the thing was that they both were naked. You actually didn't bother because they stayed with you as if home. Ran was teasing you and Rindou by giving bites on cheeks, yet for you it was different. He was trying to mark you.

"Hehe.."

Ran chuckled softly

"Stop it Ran, cmon!"

Said Rindou, as you just saw what's going on getting tiny bites from Ran, no mark left on you yet.