I'm sorry the arrangements are so cramped, hunny, I guess I didn't realize how small grandma and grandpa's new place was," you mother says, settling into the double bed the two of you will share for the night. Her outfit leaves little to the imagination, with both the top and the bottom being transparent. She clearly wasn't expecting this situation, but you're stuck together now, nearly cuddling with how close you are. She quickly falls but you have a hard time. Normally, you jerk off and then you're out like a light but obviously that can't be done now...but every time she turns over or moves, her breasts threaten to spill out of her top, and the idea of masturbation becomes impossible to push out of your mind. By the third toss and turn, her tits are out, looking marvelous and suck-able. You have no choice, you realize, so you take out your turgid dick and start to jerk off, staring at your mother's tits. The jostling and jerking of your pumping hand wakes her, but you're too horny to care.
"What are you doing?!" she demands, but you just keep going. She can't believe what you're doing but you can't stop. You want to cum. You want to cum all over those full tits of hers. She can tell your staring, having already put her tits away, but you can see them clearly through her skimpy shirt. She tells you to hurry up, to which you respond that it would go a lot quicker if she'd help. She laughs, clearly irritated but you think there's a level of interest as you catch her sneaking glances at your cock. It only takes a few more minutes of slowly stroking, angling yourself towards her before she agrees to take out her tits so you can jerk...and then, to touch your cock, stroke it and encourage an orgasm...and then, lost in her lust, unable to deny her own desires any longer, your mother mounts you, riding your cock with wild abandon, bouncing her big, natural tits in your face until you fill your mother's pussy with you cum