Pain is usually your body's way of telling you that you are doing something injurious to yourself. You'd do well to listen to it.
Additionally, most people make the mistake of thinking that since they've been lifting for a while they can just jump into any exercise with loads that are too heavy, until their body has had time to adjust to the movement.
Start light, it is probably even better to do the same weight for a specified number of sets for a couple of weeks, work on form, and add (a little) weight onto the last set once you've acclimated to the movement, then you can start progressively increasing the weight....
You may also want to try cable flyes instead (assuming you're talking about DB flyes), which are a lot easier to customize, regarding form, angle, ROM, etc.
And I prefer these to DB flyes b/c the muscle is always under tension, and the contraction is more intense at the completion of the movement. In fact, I've replaced flat benches with cable flyes, since the primary function of the pectoralis major (sternal and clavicular head) is tranverse flexion with the should internally rotated, as in a fly movement.
i have the same problem. I stoped doin db flys about 2 years ago because of it. its the only chest movement that i feel in my shoulders so i never do it anymore, but some people never have this problem and flys are great for them. If it hurts i'd stop doing them, cause shoulder injuries are really suck. Plus its not like flys are a great mass builder
I experienced discomfort, as well. For me, the pain went away after I became better acclimated to the movement, however it may not necessarily go away for you. One thing that I found that helped, was to make sure that I took the weight down slowly, not allowing the pecs to lose tension, and at the bottom of the movement, change directions into the concentric portion very smoothly taking care not to 'bounce' out of the bottom.
This helped me, however, coming from someone with shoulder issues, I would proceed with caution and see a specialist if the pain worsens or does not subside after a reasonable time for adaptation has lapsed.
In my opinion this is one exercise that is almost always done wrong, even by seasoned gym goers.
Here is what is thought of as good form for a dumbell flye in my opinion.
This is not good form at all. Look at how far down the upper arm is going. This is not necessary at all. This guy is not keeping enough tension on his chest and is basically going through his joint ROM not pec ROM. His pec has for the most part disengaged, now all that is left is the delts and bicep to squeeze the weight up. Terrible form.
Here is another dickhead.
The point is that flyes are not a bench press or dumbell bench press. It is not the type of exercise where you should be really concerned with pushing the weight. The reason is this because these idiots dont understand torque.
Good form for flyes is very straight arms, with just enough of a bend to give the bicep tendon a break. Torque comes in to play when you keep your arm straight, then you have the weight of the dumbell multiplied by the length of arm. So if you have your arms bent with an 80lb dumbell you could end up putting the same stress or probably less than if you had a 35lb dumbell with a straight arm.
The chest is also stretched much better with a straight arm. Just try for yourself sitting in your chair keeping your arms bent and trying to stretch your chest then keeping your arms straight and stretching it. Makes a world of difference. Bottom line. People are dickheads shitty ass form. Not saying that is your problem but probably.
Hahah, love your use of the word dickhead... multiple times in fact... lol. Actually though, really good points and description. Keep up the good work around here, I always learn something useful from your posts.