Is this poem about lesbian sex?

My lit teacher claims it is, although I don't really see it. She just said it was about that and refused to answer when we asked why.

Crab - Fleur Adcock

Late at night we wrench open a crab,

flesh bursts out of its cup

in pastel colours. The dark fronds attract me.

Poison, you say, Dead Men's Fingers -

don't put them in your mouth, stop!

They brush over my tongue, limp and mossy,

until you snatch them from me, as you snatch

yourself, gently, if i come too close.

Here are the permitted parts of the crab,

wholesome on their nests of lettuce

and we are safe again in words.

All day the kitchen smells of sea.

Oh and serious answers please?