Patrick Stewart, Ian McKellen Kiss on Red Carpet: 5 Reasons They Have Best Bromance

— -- When Sir Patrick Stewart, 74, and Sir Ian McKellen, 76, kissed to celebrate Wednesday’s London premiere of "Mr. Holmes" in support of McKellen's new film, the picture went viral.

But the two best friends have been supporting each other for years in amazing ways. One look at Stewart's Twitter feed and you'll know exactly what we mean.

Here are 5 reasons that the world needs more friends like these two and why they have the best bromance in all of Hollywood!

1 - McKellen Officiated Stewart's Wedding

When Stewart tied the knot in 2013 to jazz singer Sunny Ozell, guess who was there to make it official -- McKellen, according to Entertainment Weekly.

“I’m going to marry Patrick,” McKellen said in 2013 on "The Jonathan Ross Show," bringing the crowd to laughter.

2 - They Post Stuff Like This!

Homies Forever!

3 - It's Professor X and Magneto!

Stewart and McKellen both have storied, legendary careers, but as of late have starred in the "X-Men" films as respectful rivals Charles Xavier and Magneto. If these two can put their past behind them to forge a friendship, anyone can.

4 - They Are Funny

Stewart's birthday post to McKellen in May was an amazing throwback.

Then, there's Ian.

5 - The 2 Enjoy Working Together So Much, There Are Tears

McKellen admitted that he broke down in tears after the acting duo finished their run of "Waiting for Godot" in 2009.

"I recall vividly," Stewart told CBS in 2013. "In fact, it's on film. I had no idea it was going to come. But the curtain came down on our last performance, and he went into the wings and sat on some stone steps and sobbed, heartbroken that it was over."

"Yes, I was heartbroken,' said McKellen. "And then we were going to say goodbye to each other. You were going off to do other things and I just felt I would never be as happy again."

Here's more about their friendship in an interview with the New York Times: