27 here again.
I don't mean to be offensive to your friends but they are being unreasonable if that is the case. I know you were looking for advice on this matter on how to please your friends and it doesn't really help when I make obsertvations like this but all you can do is talk to them about it. It's not like you are totally abandoning them is it. Ask them to look at it from your perspective and explain to them that your relationship with this girl is only beginning so you need time to get to know each other but that they are still an important part of your life.