Most Helpful Guy
Haven't had that occur (at least not explicitly), could be fun though. I get a feeling it would be easier with NPCs than PC's though. As for disruption, you could potentially work it to make quests etc., especially if the other partner was a npc.
Most Helpful Girl
I like it a lot, but the guys i game with get all weird or turn it sexual.
Their loss... i tried one time to get super descriptive in a romantic situation and the guys were getting uncomfie and the GM finally asked/told me to stop... please... i suspect there were 5 Boners under the table... LOL