Slide a finger in her butt

As you continuously, deeply and greedily explore Scarlett's butthole with your tongue, as she moans and expresses a strange mixture of discomfort and excitement, you move the index finger of your right hand between her butt cheeks and guide it towards her rimmed hole. Powerfully you spit some saliva on her hole, making it wet. You also try to get it loose, but, for some unknown reason, Scarlett's butthole is exceptionally tight. Tighter than you ever thought was conceivable.

"Ungh!" Scarlett exclaims, pushing her butt, slightly, back and forth, you slap her left butt cheek with your left hand, leaving her clit for the moment, to remind her to keep her butt in place, then you place your left hand on her clit again and start stroking it. Scarlett is getting wet.

Carefully you place the tip of your index finger on her tight butthole and, slowly, massage the rim.

"Uhm," Scarlett tries to say, "I dunno... ah... I... ow my god, have never..."

You slap her butt again and see her head filled with red curls peeking over her shoulder. Two green eyes looking insecure yet desirably into yours. You grin. She bites on her underlip.

You exert some ****, and, after some time, push just the tip of your index finger in her butthole.

"Ow god!" Scarlett yelps, moving her butt back.

You spank her left cheek again, then you grab that left cheek firmly, and hold her in place. Pushing your finger passed the first knuckle. God! She is extremely tight! As you start pushing your finger up and down her rectum. Her rectum tightens around your finger. Scarlett moans, deeply, wiggles her butt, slightly, unsecure whether to loathe or to enjoy it. Suddenly your finger slides, quickly, passed the second knuckle.

"Ow!" Scarlett exclaims.