The thing is, your friends love you. They must do, because they've just given you at least 8 hours of their time to read your manuscript. The last thing they want to do is upset you. So, if you give any hint that they have just skewered you right through the heart, they will back off and start murmuring platitudes. (The best one I've heard was some poor soul who apparently commented on the worst novel I've ever read that it was 'almost good and nearly interesting'.) It's like the friends and family you see supporting some pretty average singer on the X Factor; either they're seriously deluded when they claim their grandson/best friend/baby brother is brilliant, or they love them and don't want them to be hurt. If you really want feedback to make your novel better, you're probably going to have to accept with a smile some comments that make you want to die.
Come prepared for this, and prepared to steer your reader. Asking them if they liked it is just asking for the answer yes. Besides, you don't want to know if they liked it (unless they're prepared to offer money for it) you want useful feedback you can act on. So prepare some questions that will encourage them to expand. A possible list might include...
Which was your favourite/least favourite character?
What did you like/dislike about them?
Were there any places where the pace seemed too slow/too fast?
Could you understand what was going on and where all the time?
Could you picture the characters/locations?
Did the plot make sense - did you ever get lost?
Was there anything you particularly liked/disliked about the story?
If you had to sum up the novel in three words, what would they be?
You're more likely to get honest answers to questions like these so be prepared to hear some things you don't like. But, even if you're in agony inside, remember that it's all useful information that you can choose to act on or not. Don't get drawn into an argument about how X was obvious, listen, make notes and then later on decide if you want to make changes. Writing is all about re-writing and good feedback is golden.