I'm going to ruin a friendship and a birthday
Why would you ruin both of those things?
I'm jealous! I'm jealous of the time he spends with his friends
It's terrible to want to ruin a birthday and a friendship. You should be nicer to your friends.
I'm alone for so long so I'm going to ruin things for everyone else.
It's wrong to take your jealousy out on your friend, you should just let them enjoy themselves.