Lesions on anus after sex.

Are you using a good lube? Because that might be your problem.

If possible, aim for a silicone based or hybrid lube and apply LOTS of it. Some brands to look into are JO and Sliquid; they tend to get the best reviews.

And are you using a numbing agent? If not, that's great, but if so, stop using it! See if any your lube ingredients contain a numbing agent as well. If in doubt, Google it!

Take your time! If your partner is rough and forcing it in, that will definitely cause injury.

Hope this helps!

I agree with Ms. Spice. Though your description wasn't clear for me, it sounds like more time and moving more slowly into pegging would be helpful. If the small cuts you refer too are more on the outside, my thoughts move towards a friction abrasion of some sort, relating to the toy you use, the possible harness you use, types of lube you use, or just not enough warm up. Secondly, it the cuts are more on the inside, I am thinking that is more directly related to warm up, pushing the body a little too far to fast, and/or your toy not being the right dimensions for your body.

Everyone's body is different, and the degree of stretch one can achieve might not be possible for others, no matter how much practice..The point is listen to your body. Any injuries or cuts in the anus/rectum can take a long time to heal due to issues of cleanliness and that region of the body. You might be re-aggravating the same cuts to be honest as they might not have had the time they need to heal, which can take months.

What you can do:

Lots of foreplay before any anal penetration, use a high quality lube, inject lube using a lube shooter to maintain lubrication, start off with just a finger, slowly work your way up to a small toy without much texture like the tantus silk, and focus just on that for a while, slowly... It can take months if not years to get your butt really comfortable to where you can control the muscles and push your limits so go slow and have fun

Here's another vote against any numbing agents for anal play. Pain is a signal and it's a pretty important one. You didn't mention what she's penetrating you with. If it's a finger, what are her fingernails like?