"Are you sure this will work?" Night Runner asked nervously, her cheeks flushed with the idea of what they were about to do.
"Don't worry! You've smuggled plenty of stuff before, right?" The gelatinous pony chirped, her smaller form still looking intimidatingly large in Night Runner's eyes. "AND I'll be much easier to hide! They'll just think you're pregnant!"
"And it's safe...? I don't want to burst or anything, y'know..." Runner asked, feeling both terrified and incredibly aroused by what she was about to do.
"Have some faith... I've done this plenty of times before! You'll suffer no ill effects from this..." A slime hoof stroked Runner's cheek gently as the slime pony smiled seductively. "Other than a desire to do it again..."
"Alright... I'm ready..." Runner turned around and nervously lifted her tail, revealing her nether regions to the slime pony.
"I'll say... you're positively soaked. I certainly don't have to worry about drying out while we're on our way." The slime pony leaned in a took a deep scent of Runner's marehood. The smuggling mare shuddered as she felt a tongue slide across her nether lips before plunging itself into her. She couldn't help but moan as the 'tongue' plunged itself in and out of her pussy.
Just as Night Runner was getting used to the preparatory cunnilingus, she let out a small scream as the 'tongue' shot even deeper into to her and spread out into what felt like a a very well endowed stallion rutting deep into her warm pussy.
"T-take it easy, will you?" Runner moaned as the slimy 'cock' slide itself in and out of her folds.
"No." The voice spoke from both inside and behind her, the vibrations traveling through the slime ponies body with ease. Night Runner could only give another moan as the unexpected sensation passed through her body. She could feel every thrust drive a little further than it's backstroke and her belly began to bloat the further it went in.