In Millie's ass

I hold my dick in one hand, and use the other to push Millie's thong to the side, revealing her light brown and very tight looking ass.

"Matt, don't!" Millie whispers.

I move closer to her ass, and spit on it, using my thumb to rub it around her ass.

"No! Matt! Don't!" Millie whispers, sounding very panicked as she realises what I am about to do, and that she cannot get away from it, nor cry out since that risks waking the home owner.

I spit on my finger, and gently push it into Millie's ass. Millie tries to squeeze her ass shut, but I easily push my finger in. Her ass feels amazingly tight, and she trying to clench it shut, but to no use as my finger continues to probe her tight ass.

I slide my finger out of Millie's ass, and position my dick against her anal opening, just leaving it there for a while. Millie feels my dick positioned right outside her ass, and I can tell she is nervous for what she knows is about to come.

"Matt, please don't." She whimpers.

I put a bit more spit on the opening to her ass.

"No, please." Millie whispers.

I point my dick at the opening of Millie's ass. Millie starts to breathe heavily, her panic increasing, and she is desperately trying to clench her ass cheeks shut, but to no avail.

Using my hand to aim my dick and hold it steady, I begin to push against the opening to Millie's ass, while Millie continues to try to clench her ass closed. It is a brief struggle, but soon I feel her sphincter start to give way, and the head of my dick starts sliding into Millie's ass.