Frustrated, that's all lovely activities! Juliette et Chocolat, mmmmm ;P
If it's very hot when you are here, I'd suggest the Jean Drapeau's Beach, close to La Ronde. The Saute-Mouton is always a winner for teens (and not-so-teen-anymore, haha), and if you want to try dining on a sight-seeing ship, the Bateau-Mouche is the most popular. In the old port there's a very popular haunted-house, Peur Dépôt. Don't go the the maze right next to it with the teens though, it's very childish. There's a Zipline in the same area too, if you're into that sort of thing, haha. Downtown there's Laser Quest, popular witth teen boys, open 'till very late.
You should try some special food too! There's Poutineville for our iconic Quebec's Poutine, The Milsa for all-you-can-eat Bresilian meat (boys like that, and there's a dancing show between 20-21h), Pastaga or Apollo Concept for higher gastronomy (they are well known Chefs here, book in advance).
There's ton to do in Quebec City as well, just walking around the old city is pretty nice. You could book an historical tour on foot, and if you like history like I do, there's the island Grosse-île that you can visit. There's the ruins of an old fort under the Promenade of Chateau Frontenac which can be nice (and cool on a hot day), and many street shows