You know, I've been thinking about a scenario where the vehicons get most of the decepticons extremely drunk during a party so that they can gangbang the higher ups without them remembering. Individual cons below:
Megatron: Since he's usually the one bossing everyone around, the vehicons have been having fun with bossing Megatron around for a change. Setting the pace, denying overloads, and overall being in control.
Starscream: Humiliation is the biggest thing the vehicons want with Starscream, their least favorite mech on the ship. Bondage and dirty talk are the main ones here, along with making him a huge mess.
Soundwave: The vehicons going at Soundwave have one supreme goal in mind: Record him breaking his vow of silence. Anything and everything will be done to get that lanky mech to either moan or squeak and the vehicons are not stopping at anything.
Knockout: You can bet that the main thing the Vehicons wanna do to Knockout is mess up his paintjob in every way possible. Scratching, biting, rubbing, any way to transfer paint, they did it. The most popular section was the inner thighs when fragging, that really drove some of the vehicons crazy.
Breakdown: Actually the only one that doesn't get fragged, purely because he's the only one that's nice to the vehicons. They dragged Breakdown to his room to let him have a nice stasis nap before starting with the others.
Shockwave: Funnily enough, only one vehicon wanted to bang Shockwave, and it was due to a major crush on him. Said vehicon dragged him away to frag in private. The whole time Shockwave's valve was getting pounded to heaven, even when he eventually fell unconscious.
Predaking: Petplay, SO much petplay. The vehicons managed to find a rope long enough to act as a collar and leash for the big guy, and they've been having fun parading him around as he crawls on all four In robot mode with his spike and valve out. The vehicons 'reward' him for tricks by stuffing his mouth or valve with a spike, and at the end of the party one vehicon lets him ferally breed as a reward for being good all evening.
Makeshift: The vehicons don't know how they managed to get this guy in the party but dangit are they taking advantage of the shapeshifter thing. Impossibly tight valve? larger than life spike? anything is possible! A couple of the vehicons even got to live out their quintesson fantasies.