Permissions
What's ok/not ok to talk about around him/her? Say whatever you want, they will probably mock you or be mean even if you are nice to them.
Shapeshifting/Bodyswitching: Shape shifting into them is fine, but I would prefer no body switching. Since they are conjoined twins it would get really confusing. If you can explain to me a situation of this that works out and makes sense then you can ask me.
Mind control: If you mind control them please ask first.
Mind reading: Give me a heads up and I will type their thoughts ^^
Deceit (Lies, manipulation, illusions, etc): Go for it, they would do the same thing given the chance ~.o
Minor insults (spiting at, stepping on, throwing non-lethal objects at, etc): Insult them all you like. They will probably fight you and they probably deserve the insults. As far as throwing things, go ahead and try but four arms for catching things is better then two so be warned. XD
Non-violent physical contact (hugging, kissing, etc): It depends. You probably don't want to kiss them but depending on the character they will act accordingly.
Sexual situations: They might rape your character if you don't mind that. They won't love your character and even getting them to rape your character will be difficult.
Fighting: They love to fight. Bring it on!
Serious injury: I would like to decide how injured my characters are but since these two fight a lot, it is very likely.
Death (intentional or accidental): Always ask first. I don't like my characters being killed randomly or inappropriately.
Special notes: I'm pretty much up to most things but when in doubt ask~