Totally agree with 4get, I couldn't spend every night with a fella, it'd drive me mad, unless of course it was a naked Orlando Bloom, Jensen Ackles or any of my other hot fantasy males!!!
Go out with your own friends, have space from each other or else you may end up resenting each other! Be independent and let him have his independence too, it won't mean that you don't love each other less!
As for how he acted with his friend, it maybe jealousy it may not be, it may be just how he and his friend are, I know a few men who like to put on a 'show' when with friends! Don't worry too much about it!
Good luck!
Apologies if this post doesn't make sense, I'm very very tired and my brain seems to have gone on holiday!!