Theres no slow dancing???

Not from a mod. When those relationship numbers are high enough, the attraction bolts in 2 or 3 territory, and double hearts, all sorts of romantic simnanigans ensue spontaineously. The relationship is strong, intense, and there's no TS4 style flirting with other sims. The consquences would be quite severe if it did. To further enliven things, there was grumpy old Mrs. Crumblebotton in the community lots. Woe betide the lovers displaying their feelings when she's around!