I'm going to assume you're referring to 'grouped' poses (incumbent on two+ figures)...
SquarePeg3D has several sets of poses depicting close combat (Heavy Hitters and Sexy Slammers in particular).
AeonSoul has some great dynamic sets. Scuffles3D, GriffixFX, ATrillionGames as well.
As for 'obvious romantic tension', I suspect artfully adjusting facial expressions between any combatants would go a long way to provide that subtext. But you might also consider some of the dom/sub pose sets.