A couple more, then you have an idea.

As you had not long ago cum, you enjoyed the feeling of Christine's still tight pussy rippling around your cock. Listening to her moan into your mouth as yet another climax hits her you think about your step-sisters, primarily Britney and an idea popped into your head.

"Christine, will you let me fuck your daughters as well as you, so that I can get all of you pregnant?" She shuddered and let out a huge moan as another orgasm hit her.

"Y-Yesssssss, just don't ever stop fucking MEEEEEEEEEEEEEE!" Deciding to quicken the pace, you reach down in between the two of you and start to massage Christine's clit, sending her further over the edge.

When Christine recovered sufficiently, you entered the final stages and started to quicken your pace, grabbing Christine around the hips, you set a rhythm, her going up as you pulled away and then her coming down as you came up. After ten more minutes of this relentless pace, you pulled Christine down hard on your cock as you unloaded a torrent of cum into your step-moms pussy.