Parents, if it's expected that you do some checking up on your teenagers' boy/girlfriends...?

Yikes. They need to move to an isted living community together. It will save them money in the long run and they will have freedom to have an intimate relationship and live together but have nurse supervision. I worked at one and it is very dignified. They have their own little house with a yard, they are just in a tightly moderated community.