Yes! They kissed in House of Crushes/House of Vertigo :)
Fabian liked Nina ever since she came to Anubis house.
We will see when Season two begins.
Yes in the season 2 finale
in season one he liked nina but didn't date her. in season two they dated then broke up because nina saw fabian kissing joy.
Yes Fabian can be trusted he LOVES Nina
yes fabian likes nina
Look up the question 'do Nina and fabian date in house of Anubis' for the answer
dating
the season 1 finale its not on the site though
Yes Nina and Fabian kiss on the lips on the last episode
No Nina and Fabian date in this house of Anubis
At the end of the 1st season and at the end of the 2nd season and in House of Hoods/House of Deceit or House of Sibuna/House of Payback one or the other