For any healthy relationship to work you have to be able have that time to spend with your friends. And to have a healthy relationship with your friends - and to be honest, if they "know you", pardon the pun, then they'll understand that you need to spend time with your partner. If people are pulling at you from both sides then maybe there's something a little off balance within the relationship. But it also depends on how you are as a person. You need to set the guidelines quite clearly, and say "I need my friends im my life. I got with you, but my friends are part of me also".