Dot.life - where technology meets life, every Monday
By Mark Ward
Technology Correspondent, BBC News website
If you walked into a room and found your partner in a passionate clinch with someone else you'd probably have good cause to worry.
Hamlet Linden chronicles Second Life lifestyles
But would you worry if those doing the kissing were characters in a game being controlled by your partner and someone else?
For some players of Second Life, a massive multi-player online role-playing game, such virtual infidelity is a step too far.
So to keep an eye on their loved ones, some spouses are paying real money to in-game detectives, to snoop on the character or avatar used by their real world partner.
Like its name implies, Second Life is an online world that encourages people to create a character and live out another existence doing almost anything they want.
It's an imaginary world without the elves and dragons people tend to associate with the "fantasy" tag.
Characters can buy their own island, create their dream house, become a clothes designer, go fishing, spend nights partying in clubs and bars and, of course, have virtual sex with virtual people.
Second Life - all the thrills and none of the danger
It is this last freedom that has driven some characters, like Markie MacDonald and Bruno Buckenberger, to turn to in-game detectives who will spy on other characters.
They will even set up a honey trap using an attractive avatar to test a character's fidelity .
Hamlet Linden, in real life Wagner James Au - Second Life's in-game reporter, says many people approach situations as just another part of the in-game play. "They put themselves in a noir-ish melodrama of no-account tomcats and good dames done wrong."
In that sense, he says, it's just like other characters who join a virtual mafia family and then wage a turf war on rivals. It's just another story for them to star in.
But, he says, the humour of the situation swiftly disappears when they realise they are about to ask the detectives to spy on someone they care about - even if they only know that person through the game.
At that point the fantasy falls away and reality rudely intrudes.
"This is where ironic narrative bumps up against real friendship, real feelings," says Mr Au.
And it must be the case that this problem is not confined to Second Life. There could be many players of online games that have serious in-game relationships with virtual friends.
One of the cases Mr Au wrote about for Second Life that involved a honey trap ended well. All the target did during the meeting with the foxy female avatar was talk about his real world girlfriend who had set the detectives on him.
To those outside, Second Life is just a game. But to participants it is much more than that largely because of the friendships they forge in the virtual world.
Second Life - its life but not as we know it
"Residents are in Second Life to role-play and create and enjoy themselves; but they also come to have genuine affection, loyalty, even love for the people they meet here," said Mr Au.
Different players of Second Life have different ideas about where to draw the line that marks the difference between harmless play and something that could threaten a real-world relationship.
Some will not indulge in as much as a computer-mediated kiss but others see no harm in virtual sex with other virtual people, especially as the person controlling the consenting avatar could be male or female.
"It's only a sort of fantasy and they are fun within safe boundaries," said Christine Northam, a counsellor with Relate.
But, she said, it was important for it to be done openly.
"It's fine if it's a game and its something you know about and are not spending hours and hours doing it," she said.
Problems could arise if one person in a relationship is a gamer and the other has no interest in being on the computer. In that case hiring a virtual detective to spy on their spouse would not be an option.
Certainly, said Ms Northam, anyone who spends hours in Second Life meeting and making out with other virtual people may well have problems in their real-world relationship that need addressing.
"If they were doing this I'd ask what function it was fulfilling, what gap is it filling up," she said. "I'd be curious about what's going on in that person's life."