The Twins and Shock hopper anal only.

[thehatrix13]

The wiki page says that both of these encounters can get the PC pregnant, however both scenes only have anal and your unable to select viginal sex

 

[valk42]

You need two vaginas to get that pregnancy

 

[TheShepard256]

The Twins' only vaginal scene is Lead Train. The Shock Hopper has two; Drain Bunnies if you have multiple vaginas, and Ride Hopper always.

 

[DrunkZombie]

Also note that you need vaginas that are big enough for the shockhopper and LDC. If they are not you will get anal only. Another person posted this same concern just last week. after increasing vag capacity was able to get vaginal sex.

 

[thehatrix13]

thanks for the help everyone!