In her mouth

You decide to let Sarah finish you the way you planned. But as good as her mouth feels on your cock, it probably won't bring you to climax alone.

"Sarah, why don't you use your hand too." She tentatively wraps her hand around your cock. "Perfect, just stroke it a bit. Don't stop sucking, though." She complies and clamps her lips down on the tip of your cock. She uses her tongue to play with the tip while using her hand to pump your shaft. The twin motions feel amazing and you feel your climax building.

"God, Sarah, yes. Keep doing that," you say.

Outside, Grace seems to be getting close too. She's reached up and has started playing with her own nipple while Tori works her pussy. Her head is thrown back and her eyes are closed. Even though you can't hear her moans, you can tell she's about to cum alongside you.

Part of you - what little of your brain is still being supplied with blood - still can't believe that this is really happening. You're looking out on two hot women fucking in a hot tub while a third hot woman sucks you off so you can cum while watching them. However this plays out with Grace and Tori after this is over, you know you want Sarah to keep fucking you on the regular. She's way more open than her shy exterior implies.

You see Grace start to hit her orgasm outside. Her body starts pulsating with pleasure running up and down her body. Her fingers dig deep into Tori, causing the girl to wince. She doesn't stop her thrusting motion, though. Sarah brings you to climax at almost the same moment. You grip her hair - mirroring Grace - as you spew your load into her mouth. She winces as your cum hits the back of her throat and starts coughing. Cum leaks from the edges of her mouth but she doesn't recoil. She even keeps pumping your dick with her soft hand. Your vision blurs for a moment from the pleasure and you feel your legs almost give out. You do have to grip Sarah's shoulder for support, but you stay on your feet.

Once you're orgasm fades, Sarah releases your cock and sits back. Her mouth is still open and dripping cum down on to her tits and thighs as she catches her breath. Grace has essentially collapsed in a pile of Jell-o as Tori kisses all over her body, face, and lips.

“I think Grace needs to throw more parties," you say.

Sarah looks up at you, flashes a smile with her cum-covered lips, and winks.