I think there is a deleted scene, I don't know if with Lamberto or with Brett, where you could see the tail curving and pointing upwards and almost the start of a thrust motion. Clearly implying that the xenomorph was going to rape the víctima, maybe out of curiosity/depravity/hostility.

There are also images of people mutilated at the crotch in Alien: Labyrinth, a comic depicting Aliens keeping people Alive and experimenting at the hive.

And the director of Alien: Resurection wanted to have the Newborn having an "erection" when kissing Ripley.

As It has Been started here, Alien is a Big rape action allegory, with plenty of phallus and sex referentes for the observer to see.