My thoughts, too. The first thing the MC should've done is say "a used condom? That's not mine! Let's have it analyzed!". Although, at this point, I wouldn't be too surprised if Kendra has the lab in her pocket, too, because why the heck not, right?
The mental gymnastics of the plot have become ridiculous. FMC now suspects MC may be a mastermind con artist that's been able to deceive her their whole relationship, but then he's as careless as leaving perfume on him when he comes back home, his lover's panties in his sports bag, and a used condom in their car.
Like, you gotta decide, woman, he's either a Machiavellian genius, or the most careless cheater ever, he can't be both. And that's also what should've clicked in her mind, if she was a competent lawyer. Which apparently isn't the case, and Kendra was right all along: FMC definitely didn't deserve the promotion, she did