I am in the process of applying to summer PhD research internships in industry (I'm in CS). Last year I had two appealing offers, but of course could only take one. This year I am still interested at working at the company whose offer I declined last year. However, I am unsure if it's considered inappropriate to reach out to the lab director again to inquire (this is how I approached it last year). It's not as though I burnt any bridges previously, it just feels strange, kind of like saying "Hey, I didn't want to work with you before, but what about now?"
Is this appropriate? It is research and I am in a research program, so I don't want to ruin potential future collaborations, and I hope I have not already done so by declining a previous offer.
And more generally, if inappropriate, when making a decision between multiple offers, should it factor into your choice that you may declining for this, and all future, internship opportunities?