Isn't this the solution?
"A
common law marriage is one in which the couple lives together for a period of time and holds themselves out to friends, family and the community as "being
married," but without ever going through a formal ceremony or getting a
marriage license. "
So it technically isn't incest. Like, if the mc wants to fuck the other girls, just get the main chick (Nicole in this case) to agree to sharing the MC.
For reasons as to WHY they'd do so in the first place,
"
- They are fearful that getting married will cost a lot of money;
- They are put off by all of the formalities of a ceremonial wedding; or
- Because they simply don’t have the time or the desire to complete the legal procedures required for a formal marriage.
"
They could just hold a mock ceremony. It already looks pretty informal. To further cement the informality of the situation, just place the chick in some really kinky clothes. I.E Bridal gown with the important bits cut out (personal fetish of mine I'd love to see more of).
In the
CONTEXT of the story, you could just use anything regarding your setting. But what I suggest is; you can choose common-law marriage if you want to fuck all the girls including ur chick, but you could go for a
LOCK-IN decision by doing a formal marriage (Epilogue? After all this gang shit is settled) so you can't mess around anymore but you get your waifu I guess. This way you don't break any rules.
saddog