Shake it baby!

I mean, I get (kinda) why Duke Nukem is there ("hell, I'd still hit it") but DoomGuy is totally coming out from the left field. (Unless it's reference to the fact that you can 'RIP AND TEAR' her tail)

Rip and tear is probably it, yeah. Duke summoned him for some fun but he's gonna scumbag it up and cut the tail.

Duke is there because of the shrink ray gun he has (in Duke Nukem 3D, you can use that to shrink enemies into pithy size and step on them), to bring Priscilla to size.

As for the Doomguy, he has this "Tonight, you." look. Rip and tear inbound.

Death by Snu-snu.