Hmmm... Depends a little bit on what they're into. Teenagers can be quite tricky

. Are they girls / boys? And how old? If they like 10 pin bowling they could take a short cab ride round to the Bel Air hotel. And there's an ice skating rink in Yasmine Hammamet, a slightly longer cab ride away. I used to quite enjoy both when I was a teenager, but maybe this just isn't cool enough these days

!
There's always the hotel discos and disco bars, but this would depend on if they're older teens. (And most of the hotel discos are unlikely to be considered remotely hip or happening by any teenager!). There's a couple of cafe bars down the road to Citronniers - the El Dorado is especially popular.
There's generally various activities arranged by the animation staff during the day - there should be a board up in the hotel showing the programme, but these are aimed at everyone, not just teenagers.
A.x