Names have been changed. Sorry for extremely long post.

I (24f) have been friends with Beck (23m) for about 6 years. We met when my mom sold his mom one of our pups from a litter. We became good friends over the years.

The girl, we will name Amy, used to go to high school with me. I knew her through a group of friends, but we weren't friends. Her and Beck met in college sophomore year. He instantly had a crush on her. Redhead, slender, witty, etc. Perfect girl in his mind.

Beck asked Amy if she would date him, and she said she couldn't because she was going overseas for a trip over the course of 6 months and didn't want to date anyone. He understood. A week later, Amy got a bf...and this was my first red flag.

Fast forward to a couple of years ago. Amy came back, broke it off with the one guy, and started hanging out with Beck. He was excited but I cautioned him to take it slow seeing that she blantantly lied before her trip.

They hung out. His feelings got stronger. She started developing some herself for Beck. The closest contact they had was a kiss on the cheek and a hug, which to Beck was a big deal cause he didn't have a gf before.

Things were getting harder in Amy's life. Family issues, self issues, etc. Last year, she committed suicide. It was sudden and unexpected. I was the person who broke the news to Beck. He was distraught and very upset.

Now to the point I am making in this post. After she passed, he was pretty much calling her "his gf". Again, like I said before, kiss on cheek and hug. I told Beck this was a bad idea since they never dated and they were not official. I have had loved ones pass in my life, and if one of my good friends after I passed started calling me his gf, I would expect someone who knew the truth to correct the situation.

I tried. It failed.

Every time a major thing happens, he somehow brings it back to Amy, which sometimes is sweet, and sometimes is downright annoying. Recently, he has posted photos of her saying she was "like Scarlett Johansson's Black Widow" and other things. Part of me wants to confront him on this and tell him to stop being in this fantasy world. Amy's mom is even willing to give him part of Amy's ashes. It's creepy.

What do I do without screaming at him that they weren't together and he needs to get over it? Or how do I try to ignore my friend's love obsession?

Tl;dr My friend's crush committed suicide last year and he is obsessive af about her, even calling her his GF. What the hell do I do?