My dad's coming with me for a couple. I don't know if he'd be out of place/bored at certain times and he has no problem staying back if that's the case, but certainly for certain portions like tours and dinners and such I think it'd be fine, they do allow guests after all.
Then again you do risk always being remembered as the guy who brought his mom to the open house.p
I've seen this opinion before, who cares? If you're coming fresh out of college and traveling a certain distance to visit, I don't think its odd at all. In the case of the stereotypical parent who's constantly asking questions, etc., I can understand but if your dad or mom is just there checking out the school and acting normal it shouldn't even be an issue. Besides this is an admitted student event not a registered student event, so the majority of people are making a decision whether or not to go compared to other schools they've been admitted. Many of the people in the group likely won't even be your classmates. And if they are, so what, you're not taking your parent with you once school actually starts.