You will instantly know if you're being entered in a bad way, because it'll hurt a lot. And that's the time to stop things.

Be gentle when you enter another person: after you're in, you can use healthy stroking, but not at first; don't plunge in like a high diver. You should slide in with a firm, easy pushing, If not, try again later. The anus may not be either totally relaxed or tight: it doesn't have to be gaping wide open- but if firm pressure doesn't work, don't go on. The best indicator of trouble is pain - a little is usually normal or all right, especially of the ass-person is inexperienced, but a lot means stop. If the penis is really large, some extra stretching may be necessary, and this may take a little practice for the anus to get used to. You can insert your penis in just part way, and then withdraw, so that their anus will become adjusted to accept this mount. The anus is very flexible, but it may take some practice - try inserting a little, then full insertion later, followed by gentle movements and then finally moving as comfortable. This gradual approach, in many matters, is usually the safest and most secure way.

From all the foregoing, it may seem like anal intercourse is a very complex activity. But actually it's a simple thing, and comes easy with an easy mind. It's another way of sharing bodies and feelings, meeting and exploring the world of ourselves. It can be a way of pleasuring, growing, loving, a nice pastime or a meaty pursuit.