So you invited me to your wedding/engagement/birthday party.  I am excited and feel honoured that you want me to spend the celebrations with you.  But then you message me - "Bring your camera with then you can take some nice pictures for us..."  Sound familiar?
So if you invite a friend who is a doctor you ask him to bring his scalpel to lance a boil for you and your plumber friend to bring his plunger to unblock your toilet.  Or your hairdresser to bring her scissors to give you a quick haircut... I think not.
So why is it ok to ask your photographer or videographer to bring his/her equipment and then practice their trade - which they charge money for - at your event FOR FREE?  When you have never booked a paid shoot with me - EVER.  Well the answer is simple - IT IS NOT OK!
See, if you see me as your friend and you want me to share your special event - you invite me as your guest and enjoy the festivities WITH you.
If you see me as a photographer whose style you admire you book me and I quote you and you PAY me to shoot your event.  That is my profession - my source of income.  And I would not feel offended either way - in fact in both cases I will feel flattered.
But to invite me as a "friend" and then have the audacity to EXPLOIT me - now that is an insult and would result in me not attending your event and I will remove you from MY friend list.
Maybe people think that being a photographer is easy.  And with digital cameras it "does not cost anything" to take pictures. Right? WRONG!
There is a vast difference between taking snapshots and actually paying attention to light and composition to ensure a perfect picture.  The second does not happen while sipping wine and laughing with friends.  It takes effort and planning and WORK! So you don't enjoy the event - you actually WORK!  As for not costing anything.  My equipment is expensive and I worked damn hard to be able to afford it.  It is insured because if your drunk Uncle Bob knocks it off the table neither him nor you are going to replace it. And any digital camera has a certain number of clicks then it has to be service or replaced - so no it does not cost NOTHING to take a picture.
So I am your friend and I am a photographer, and you like my style of work - support me.  Do not ask for a "Friend Discount" or a free shoot.  If you can not afford a shoot at that moment - ask me for a payment plan or another package.  And no not a "But I only want three photos" plan.  The set-up and planning and travelling and insurance etc. for three photos or 30 photos are more or less the same... and to get three perfect images is NEVER just three shots.
I love my friends and family - and if you invite me to your event, I will probably offer a shoot as a gift - but to shoot the event when I am also a guest - been there - done that and never again.
And if you do receive a photoshoot as a gift - please be aware that to me you are now a client and time and effort goes into the planning and set-up of your shoot.  So please do not just not show up or show up late. Respect my time and knowledge and effort they way I respect you.
I can assure you as a photographer I work hard, long and irregular hours to accommodate clients and their needs.  Then I edit and market and do other admin as well.  I do not get sick leave or personal days - the show must go on.
I once did a wedding after spending the previous night in hospital with my sick baby.  And when the bride arrived at the church I fell and broke my toe and torn ligaments - but I finished the wedding - because I am a professional and my client's needs are my top priority.
I have spent hours learning new techniques and skills and have spent a lot of money setting up a studio and bettering my equipment. So instead of expecting your photographer friend to render his/her services for free - support them. And if you do not relate to my style, be a friend and be honest and tell me why you do not support me - no hard feelings.
So remember, photography is a profession, not unlike hairdressers or doctors.  And I have bills to pay as well.  And yes I may be your friend - but that does not pay the insurance/rent/wine at the end of the month. 
So when is the party - I LOVE a celebration - but I also LOVE taking pictures - so either way let me know!