I mean, that thing has a mouth within a mouth. Head recipients will get the experience squared2. I guarantee you that it's very skilled with its tongues, too. Not to mention how wet and fleshy its mouth probably is. I guarantee you the foreplay is wild and would be the ride of your life. It's a being of pure hatred and hunger so it can probably last for hours straight, subsisting on your juices. In addition to this, the Xenomorph has a tail, which comes with limitless possibilities like choking or anal insertion. The noises it makes are probably very exciting in the moment, too, not to mention the adrenaline rush that the fear of encountering it would provide.