How do colleges know if you're doing multiple degrees at the same time ?

[videogamesrock]

This is an example of university in loco parentis. If you can get into two schools and do well at both, it's none of their business what you do outside their school.

What does a school honor code have to do with this? I've never seen anything from any school forbidding this and I have multiple degrees from multiple schools and have done something similar at the graduate level.

Some schools require you to tell them if you are seeking a concurrent degree, not all, and obviously if a degree has been conferred. Each school has different requirements. Screw 'em, you do you!