They can, but you can't say a guy that cleans the cum out of his girl (after she was cramped by her 'bull') isn't a cuck. That is just not how that relationship works.
And we are talking about word definitions here - basically all of the aforementioned kinks involve love: you love your girl enough to share her with other people, or you love her enough to let her have other lovers while you stay loyal. Both can be mutual, but one is more... sinister than the other, or at least it has the most potential to turn into something that is no longer mutual (cuckolding).
I dunno to which extent Bobbyboy is planning to implement these fetishes into this game, but it is safe to say that NTR will be a part of it at some point, sharing definitely. Cuckolding? Tough to say.