Get Laid Tips

I have several questions, but here is a brief overview:

A guy at college & I have been flirting for around a year & a half. Last week him & his girlfriend broke up, & I broke up with an ex around a year ago, although we still act very much like a couple. On Monday night this guy at college (I’ll call him X) slept at my house, because I was alone & needed someone round for security. Things got pretty heated & although we didn’t sleep together, a lot of other stuff happened. The next morning the same happened, & since we have been meeting up in secret at college so that our exs don’t find out, & we don’t lose friends. I felt very much in love with my ex until all of this happened, and now I can see how passionless the relationship was, & how unhappy he made me. This is the happiest & most confident I’ve felt in a long time. So… questions…

1. How do I hide the fact that he is my fuck buddy to people?
2. Is this a good idea at all?
3. How do I keep him interested?
4. Do you think I will fall for him?