Is this a bad way of photographing 2 people?

My parents had an anniversary party and they asked me to bring my camera and take photos of everyone.
all i've got is my nikon fm2, which is a film slr… So that's what i used.

they don't seem to like some of my photos
2 of my photos are very similar to this
http://karlgrobl.com/blog/wp-content/upl…
(i still haven't scanned my photos yet, but they look a lot like this)
my dad was sitting right next to my mum and i took the photo from their right side.

i put my mum in focus, and my dad out of focus and took another where my dad was in focus and my mum wasn't… You get the idea.

they didn't like it. They asked me if there was something wrong with my camera.
they just don't seem to understand the idea.

do you think this is a bad way of photographing two people?

i did take a few other photos of them, where both of them are in focus and looking happy but they look like typical married couple shot.
i guess i was trying to make it a bit more interesting…

feel free to shout out your opinions.

Added (1).

try this if the link doesn't work

Site says "Whatever you are looking for can't be found".

Your depth of field is too shallow, us a wider angle lens setting
or move the subjects the same distance from the camera
Its a good shot if it was of one person

http://en.wikipedia.org/...h_of_field

The point of using a shallow depth of field is to isolate the subject from a cluttered background (eg to make one person stand out from a crowd).
If the subject is TWO people then they both need to be in focus, otherwise the image is just of your Dad or of your Mum (ie a single subject).

What you have done is excellent - to another photographer. But to the general public a waste of time unless the parties were NOT related. At wedding, family gathering etc, people generally want everyone in focus.
I think you have great talent in doing this just the wrong audience.
As a photographer I do not take bad pictures, just poor explanation to the audience. Keep on picture taking.

It's pretty normal for me to use a shot like that in a wedding, the trick is not to get the other person too out of focus. I have used it with the bride looking at her flowers or her parent's wedding picture while the parents look on, the bride looking at her self in a mirror while mom looks on slightly softly focused, or as a portrait in a church of the bride while the groom looks on. The sample you show of the two boys would be too soft to use in this instance. Perhaps it was too soft, perhaps your parents just don't relate to this type of image. Without seeing it I can only guess. Since you covered your bases by giving them other images that they liked, I would pass it off to an experiment. Give yourself an "A" for effort!

You've just had a hard lesson, if you have a 'commission' you have to give the customer what they want.

Over 90% of my work is 'run of the mill' stuff I can do in my sleep, ask a man in the street to critique a picture and the first things they look at are, is it in focus and is it exposed correctly? The picture you link to would be one of the 10% of pictures for me. For people who don't know that there's a relationship between the two sitters it's a great shot, it would get placed in photo competitions, but it's not what your parents wanted.

At parties where I can't control the surroundings I just take 'recording shots', maximum DOF lot's of light (usually flash) to keep shutter speeds high, because experience has taught me that's what people want.

Why not give them a 'portrait session' in more controlled surroundings, you might want to try closing the aperture some, placing them close together so the DOF has both in focus, increase the distance from them to the background so that is blurred. It's all about controlling the DOF and the lighting to get the result you (or more importantly your clients) want. The recording shots are fine for recording the anniversary, but a good portrait shot is the one they will hang on the wall.