My boyfriend turned gay after had a threesome

I had threesome when I was very young, about 16 years old. It was with my boyfriend and his friend with the help of some kinky apps. Now, we have separated for a very long time. The reason we break up is exactly because of that threesome dating. His friend was a boy too. We had a very nice experience. Not long after that, my boyfriend told me that he couldn’t see me anymore, because he found that he was a gay. I was shocked. As expected, his boyfriend was the friend who we had threesome with.