Erotica?

Not quite Spring!

Well, tomorrow is Valentines Day and a lot is being said about "Fifty Shades of Grey". Not really understanding such issues, I thought I would go out and see for myself. I didn't have to go far as can be seen by these images but I'm still wondering how they could be regarded as erotica? Explanations welcome!

Fifty Shades of Grey

Please let me off my lead - I PROMISE I will be good! I don't think so!