Not in a legal sense. For all legal and financial purposes the parties are married in good faith even if there are other relationships behind them. Marriage fraud usually refers to situations such as:
1. My friend has cancer but no insurance, so I’ll marry them to give them access to mine, then we can divorce once they’re better
2. I don’t have a close relationship with this person, but they want to become a citizen of my country and offered to compensate me if we pretend to be in a relationship to get the green card
3. I split from my ex but never bothered to make the divorce official before moving across the country, but now I met someone else, so I’ll just go through a wedding without voiding the last one
I don’t really get why they’re so afraid of the marriage contract being revealed by that scumbag. Sure, they aren’t in love, but they both have full citizenship, are legally married, living together, and basically do everything that a real couple would do, so it’s not like there’s any fraud involved. Sure, it might be a bit awkward, but people get married for all sorts of reasons, to meet mutual needs, to care for an unexpected child, to have kids before biological time runs out, etc... ╮( ̄▽ ̄)╭