Translation:Will your parents come to the gallery?
Unfortunately, your second thought. It is much more common to use "seu" since você is third singular person. However, people mix them up all the time. It's so natural! =) So, you can find it anywhere, but you have to avoid this when writing since it is grammatically wrong.
Never mind. You're not bothering at all.
OK, cool. Is this more common in some parts of Brazil or Portugal than others? Mixing up the teu and seu, I mean.
Also, one small thing: I think British people might say "never mind" like that, but at least in the U.S. we would say "Don't worry about it" or "It's all good" (super colloquial). Not trying to correct you, just a comment. I had to actually go look it up!
Thanks again, man!