In the world of objectum sexuals (people who form sexual relationships with objects) it seems monogamy isn't an issue. For instance Naisho, an average-looking American woman, has been at it with the Golden Gate Bridge, has a fence for a lover in her bedroom, used to be in love with an archery bow and is now officially married to the Eiffel Tower. This, of course, is the final part of five's fascinating and odd series Strangelove. Last week we met two fellows who had sexual relationships with their cars (click here to see a review of it), and it seems that many people I know watched it and had an opinion on it. Yes, having sex with inanimate objects certainly gets a conversation started.

Credit to the filmmaker here - it would be very easy to make a documentary series that points and laughs and sniggers at such things. But this managed to keep a very even keel, even though the subjects' habits were some of the strangest ever seen on television.

The two main questions I had when coming to this film were how? and why?

Let's do the hows first. Naisho used to be in love with her archery bow, Lance, and even won world championships with it. But now the (sexual) relationship is over they no longer have that special synergy. She explained that she was attracted to the good looks of Lance ("oh, he knew he was good looking") and that they made love. She now has a fence in her bedroom, which she sits on, stretches out on, kisses, strokes, makes connections with. Naisho told us that this fence is an amazing lover. In the opening bit, when Naisho explained that she was in love with the Golden Gate Bridge, she had a piece of it in her hands. She said that she makes loves with this piece of the bridge at home. Naisho is also in love with the Berlin Wall, but more of that later.

We also met a Swedish woman who is the godmother of the small objectum sexuals community, who can now converse via an internet group and not feel so weird. This Swedish woman has never had a relationship with a human before, and has been married to the Berlin Wall for 30 years.

Then there was another woman called Amy, who was in love with the Empire State Building, used to be in love with the World Trade Centre, and is now fully obsessed with a fairground ride called 1001 Nacht. When she got together with Naisho for a visit to New York, they both went to visit the ride. Amy was so very happy I thought she was going to explode. She wriggled around with the ride, told 'him' that she loved the shape of 'his' counter weights and that every time she made love to him at home (all objectum sexuals make models of their loved ones at home so they can, well, y'know) she shouts "I want your fluids! I want your fluids!" at the point of no return. Amy then laid on her back and writhed with the ride, covering herself in 1001 Nacht's grease and oil.

So we get to the whys. It turned out that Amy had had a tough life - her dad deserted her and her mother, her mother got cancer... and she was diagnosed with all manner of autistic-style disorders. One of them was Aspergers, which prohibits sufferers from enjoying emotional relationships with humans. Amy got her love from objects - objects that wouldn't leave her or wouldn't hurt her.

Naisho's story, meanwhile, was harrowing. Orphaned at an early age and passed around from foster family to foster family, she was sexually abused as she was growing up. When she joined the military, she was abused there as well. She was thrown out of the army for being weird and developing a relationship with a Samurai sword. It was the same thing - she seemed to enjoy relationships because she felt safe with them. Objects were not going to hurt her.

Naisho took a trip to visit the Berlin Wall, her most complicated lover. The Wall itself is a symbol for bad things, but Naisho explained that, like the Wall, she was brought into this world and then rejected. She understood the Wall's pain.

And I sort of understand that. I'm glad the film answered the why questions, because the these answers were very harrowing and explained a lot. If we didn't have those, we would have come away thinking that these women were super-weirdos. In fact, they're expressing love and receiving love in very non-threatening ways. Leave them to it, I say.