Honestly I always thought this was one of the rudest things you can do. You insist some one comes hang out with you and your bf/gf, then all you do is sit near by and make out that is very rude. I made sure I never did this to my friends and I told them to never do it to me or others. Stuff like this always made me mad. A quick kiss is ok, if you cuddle with each other ok, but when it looks like hands are about to go other places and clothes are about to fly get a fucking room.
My parents forgot my 15th birthday and I told my friend who insisted he throw a not-so-surprise surprise party, but on the day of he forgot to invite anyone so he just brought his gf and my bday was me sitting on the couch attempting to watch Big Hero 6 while they made out for 2 hours lol
I believe you know the answer already.