There are two main components to be handled:

1. The question
2. The answer

For (1), you can either choose to say

Please ask your question after I finish this part

or take the question right away.

For (2), I usually prefer to ask the classroom

Is there anyone who wants to answer this question?

If someone volunteers, and in your case someone always does, then I let the one who asked the question listen to the answer. Then, the important part comes:

Did you understand the answer?

If the answer is understood, then everyone is happy. If not, then I proceed to explain the answer in my own way.

At the end of the day, the most important thing is that the students understand as much as they can, regardless of the person explaining. Of course, it is sometimes annoying for a student to interrupt your answer arrogantly. But you can always turn this situation into your advantage. Remember that there will be a question where someone else wants to answer, and then your lecture becomes interactive. Interactive lectures, in my opinion, are the best to follow and the most enjoyable ones.

There are two main components to be handled:

1. The question
2. The answer

For (1), you can either choose to say

Please ask your question after I finish this part

or take the question right away.

For (2), I usually prefer to ask the classroom

Is there anyone who wants to answer this question?

If someone volunteers, and in your case someone always does, then I let the one who asked the question listen to the answer. Then, the important part comes:

Did you understand the answer?

or rather, as @Bob Brown pointed out,

Is there anything I should explain in more detail?

If the answer is understood, then everyone is happy. If not, then I proceed to explain the answer in my own way.

At the end of the day, the most important thing is that the students understand as much as they can, regardless of the person explaining. Of course, it is sometimes annoying for a student to interrupt your answer arrogantly. But you can always turn this situation into your advantage. Remember that there will be a question where someone else wants to answer, and then your lecture becomes interactive. Interactive lectures, in my opinion, are the best to follow and the most enjoyable ones.