I think the OP should be commended for his attitude, and not be seen as being controlling or judgmental of his female friends. I think he sincerely concerned about his own soul and his sisters in Christ. That is commendable! As an older man I can attest that at any mans age, you women dont realize how hard wired we men are to the female form! Yes, it is our responsibility to respond to the natural impulses God gave us…immediately. However, women to have a responsibility to dress modestly too! What that means may differ, and a man should not demand that a woman dress according to his dictates of modesty. Women have been controlled by men for centuries, so we should be sensitive how we raise the issue. But what the OP wrote, he simply asked about how he could raise the issue. Simply being vulnerable and letting his female friends know his concern seems perfectly virtuous! He was not suggesting he force the girls into a burqa. So, let your friends know how you feel, and simply ask if they could cover up a little when youre around or otherwise you may have to pass when asked to go the beach, pool etc. with them. Dont expect them to change, and be ready to remove yourself from their view.
Youre not alone as a young man. I had a younger friend whos wife liked to wear revealing clothes. I simply apologized to my friend that I caught myself gazing at her exposed body parts, and simply joked that she cover up or Im going to have to be obvious in my avoiding looking straight at her. I wasnt demanding my friends wife cover, up and i certainly wasnt going to talk to his wife directly about it. But I wanted him to know I was sorry for disrespecting him and his wife for looking at her, but also that the way she dresses doesnt help. It was up to him to decide what to do. He must have suggested that she dress more appropriately because from that point forward, she did. And it wasnt because she caught me, because she dressed like that frequently and Im sure she caught my gaze before. The point is , there is nothing wrong with asking in a polite manner. It shows you respect them as well as yourself.
You could simply say: “you know girls, youre very attractive. Im sorry if youve caught my eyes (if youve actually been guilty), but your bikinis dont help. Since I dont want to be disrespectful, ill try not to, look and if you want to try to help me you could cover a little too.” You can say it in a teasing way , without being too serious and still be friendly and get your point across. And if they tell you its just your problem or simply dont cover up, you know what you have to do.
God bless you for your concern! Your future wife is going to love you for that!
I don’t want to be controlling but I want them to be aware of what that causes in men. Especially young men like myself. Most of my female friends are Catholics and a good amount of them are practicing Catholics.