There's no sex in this poem—except for maybe when Coleridge wonders about what's going on in the town this late at night (we're joking… we think). It's aimed at adults, obviously, but it's very concerned with the G-rated world of children and babies and pleasant natural scenes. Coleridge reflects on his own relationship with Nature as a child, and imagines his son achieving a closer state of communion with the natural world.
Plus, the poem is pretty concerned with God and spiritual things. It has a lot less to say about the relationships between men and women (like, oh… nothing) than it has to say about the relationship between human beings and God. So, if you want a really sexy poem, you might want to look elsewhere. Coleridge (and Wordsworth) are much more focused on Nature and spirituality. (Early John Donne or Shakespeare might be more your style.)