It's so fun!
Everyone who's playing stands in a circle with one person in the middle. The one in the middle chooses a person and goes up to them and says "Hunny, do you love me?" and the person they're saying it to has to say "Hunny, I love you but I just can't smile." all without smiling/laughing. If the person smiles, then they are the one now in the middle and choose a new person, if they didn't smile, then the person who asked the question is still in the middle and choose a new victim.
The best part of the game is to see how people say their line, b/c you want to make the person smile, so it can get pretty suggestive depending the group XD
And there's two ways to play it as well: Physical and verbal.
Physical is basicly, you're aloud to touch the person and there are different levels on how you can touch them, which usually depends the group/person.
Verbal is you're not aloud to touch the person in any way, and you just have to make them laugh with how you say the line and body/face movement. This is harder to get people to laugh.
This is just the perfect game for a yaoi/yuri fest XD
And especially if people try to do it in character, it makes for some interesting fun.