ok , Good work you did,

If you like your friend please kindly tell him, but one thing for sure is that he will foolishly ask the girl because he is in love and the girl will deny it. So the best thing for you to do is this. Call the girl tell her that you want to have a word with her when she comes put ur phone on voice recorder and start asking her why she didn't love ur friend that ur friend love her so such, that since she told you her mind toward ur friend that u no longer feel comfortable. My guy trust me her reaction will change and she will start yabing ur friend, but before you show ur guy this record first explain to him what makes you go too far for it.
Advise for ur friend.
Your friend should quit the relationship fast before she do.
Your friend should pretend that nothing happen and keep fucking her without given her any thing.
Your friend should invite another girl in his house when she is around.
Wish u luck

Ders a difference from telling ur frnd d truth ND wat u tink u should do now....ur NT d gf..she shuld tell him herself,ND by d way he will even ask u "how did u knw my gf doesn't love me hav u been talking to her more Dan me" wen u tink ur doing d ryt thing you end up regretting it dear