<human>: Me (m20) and my girlfriend (f21) are having a threesome tonight with my best friend (m21)  . It was my idea from the ground up and we have a really trusting relationship and we have a great sex life . Allthough thismorning i feel as if my gf and my best friend are more eager than me now although they were kinda unsure to begin with . Im worried now that i get jealous of what he does to her and if she secretly enjoys it more i notice their exitement for it and find myself now dreading it . Is this just nerves or a big mistake ? Not looking for solid answers just some advice maybe ?

Can you summarize the given text in a few sentences?
<bot>: threesome arranged for tonight , is it good or bad to want to cancel it ? And should i before its too late