There is a professor in the city I am currently living in who does some interesting work. I would like to sit in on his lectures, but I do not know how to ask him. What is the best way for me to ask him to attend or audit his lectures or seminar? I don't want to come across as rude or imposing myself on him, esp. when its about seminars which are maybe not so big.
Also, relatedly: I am not sure if I would be able to attend every single lecture because I will have a lot of work to do the upcoming weeks. So I am not sure how to best ask with this in mind. If he says yes and I am not coming to one of the lectures -although I would love to- will it maybe look very bad?