Why not?

You pull her completely back into you and feel her ass against your hard shaft. You almost groan in pleasure, and notice that she doesn't move, but stays looking at her phone.

She gives a slight smirk to you, and slowly starts to move her hips.

You look around. Everyone is preoccupied with something else, and you just look like a couple hugging right now, but you know it's more than that.

Alison starts moving her tight ass cheeks, barely concealed by pants, against your jeans, pressing into your rock hard erection.

You close your eyes and refrain from making any noises as she rubs herself on you. You grab her by the waist, pretending to look over her shoulder at her phone.

You pull Alison onto you, feeling her ass push onto your dick and hear a soft moan escape her lips. As you continue to pull her against your cock, she starts to rub up and down.

Her hands seem to be shaking a little bit and you whisper into her ear.

"I know you like that."

She almost moans again, and you can't believe this is happening right now.

Your cock is lodged between her ass cheeks now, and you feel them squeezing around you. She purrs in pleasure as she feels you lightly working her ass.

When you really start to feel yourself coming close, you step back from her. She turns around and smiles at you.