< Meine Schwester schluckt Sperma

• Benita Milano probably uncredited
• Lara [2] probably uncredited
• Marta [4] probably uncredited

Males:

• Conny Dachs
• Hubsi
• Ronny Rosetti
• Steffen Schlang
• Vanessa (she-male, bottom)

Scenes:

1. Benita Milano, Vanessa, Hubsi, Steffen Schlang
2. Benita Milano, Marta, Vanessa, Ronny Rosetti Hubsi, Steffen Schlang
3. Benita Milano, Marta, Ronny Rosetti
4. Benita Milano, Marta, Lara, Conny Dachs, Ronny Rosetti
5. Benita Milano, Marta, Lara, Conny Dachs, Ronny Rosetti, Hubsi, Steffen Schlang

All in all it's just a single scene in which permanently some of the actors are joining or leaving.
The film wasn't seen in it's original version, but via the compilation Best of Inzest 4 (Puaka GB 212988), see here.