Like I said, using contraceptives won't lead to more fun. It will lead to more unwanred pregnancies.
Habit Persistence and Teen ***: Could Increased Access to Contraception have Unintended Consequences for Teen Pregnancies?
http://www.econ.duke.edu/~psarcidi/teensex.pdf
The persistence in sexual activity is such that policies that affect access to contraception will have very different effects in the short run than the long run. Our results suggest that increasing access to contraception may actually increase long run pregnancy rates even though short run pregnancy rates fall. On the other and, policies that decrease access to contraception, and hence sexual activity, are likely to lower pregnancy rates in the long run.