Yes, but be weary, when you do that to a guy that has interest in you it will seem as positive feedback that you may feel the same way. But because you are thankful and are doing it out of kindness, that should not stop you. If he keeps trying to do it don’t let him the next time. *this is coming from a guy. I haven’t gotten many thank you’s from girls after buying them drinks, your one of a kind. :)