Spicy marriage-in-trouble romances? Oh, absolutely! One that immediately comes to mind is 'The Unhoneymooners' by Christina Lauren. It's not exactly about a marriage crumbling, but it nails that tension between two people who can't stand each other yet are forced into proximity—with plenty of sizzle. The banter is sharp, the chemistry undeniable, and the slow burn is delicious.
If you want something with more explicit marital strife, 'The Bromance Book Club' by Lyssa Kay Adams is a gem. It tackles a pro baseball player trying to win back his wife after she discovers his... let's say, performance issues. The guys in his book club teach him romance novel tactics, which leads to hilariously sweet and steamy moments. The emotional depth here surprised me—it’s not just spice; it’s about vulnerability and communication.