Ever fall in love with a romance that starts with a “whoops”? Whether it’s a wild one-night stand, a secret billionaire baby, or a surprise pregnancy that turns enemies into soulmates, these stories serve up all the feels—and then some. From fierce single moms to unexpectedly swoony dads, this list has all the chaotic charm and tender moments you crave.

And because we know some like it sweet while others like it scorching, we’ve rated each book’s spice level from 1 to 5, so you know exactly what kind of heat you’re in for. (Spoiler: some of these might melt your Kindle.)