Some, mainly Ashkenazim, hold that glass dishes must be separated between milk and meat. Some, mainly Sefardim, do not. May the former eat on the latter's glass dishes?
After-the-fact, Ashkenazim rule that glass never "treifs" up food. The question is whether I may go eat at his house in the first place, is that called "choosing to use glass dishes"?
An easy way out is Rabbi Moshe Heinemann's view (shlit'a). From the Star-K:
Q: There are many varieties of glass on the market. Do arcoroc, duralex, pyrex, corelle and crystal have the halachic status of glass?
A: Yes, they do.
Q: Can one use the same glass utensil as a Kli Rishon, to cook and bake both dairy and meat dishes? A: No.
Q: Can other glass dishes, such as salad bowls or casseroles, be used for both dairy and meat meals? A: If the food is cold, or the glass dish is used as a Kli Sheini, it may be used for both dairy and meat meals. Unless it is used on the oven or range, a Kli Sheini is okay.
In other words, even Ashkenazim may use the same glass plates, as you don't bake directly on the plate (it's used as a kli sheni). So you're fine unless you know your Sephardic hosts put their Corelle plates in the oven, or use the same Pyrex baking dishes for both meat and milk -- unlikely.
I spoke to Rav Chaim Pinchas Scheinberg, Zatzal, about the Halacha in this case. He told me that Sephardic Jews rule according to Rav Yosef Karo, and therefore use glass dishes for both meat and milk, while Ashkenazic Jews conduct themselves according to the opinion of Rav Moshe Isserlish, therefore refraining from the use of glass dishes for both. But, he said, because there are different opinions regarding the Halacha, there is room for leniency in cases where extenuating circumstances exist (for instance, a Ba'al Teshuvah who is going for a family visit where the kitchen is not kosher, but glass utensils are used). Should such a situation arise, you should contact your LOR for advice.