Another funeral one.
Many years ago my fil's brother died (so dh's uncle). They attended his funeral, along with many other people. Fil sat with my dh and dh's bro, amongst other relatives.
It was a 'rent-a-vicar' doing the service so they were reading from a script with the decedent's name inserted into the relevant blank spaces and other blank spaces filled in with relevant details etc. Everything was fine until there were a few sentences which were celebrating various aspects of dh's uncle's life. It went like: "We are here to celebrate the life of (insert name). The life of (insert name) was long and fulfilled. The life of (insert name) touched many people, as evidenced by all the people here. The life of (insert name) ..."
Great, except dh's uncle was called Brian and dh, bil and fil are all Monty Python fans. So for a short while every sentence was The life of Brian this, the life of Brian that... dh, bil and fil tried not to giggle at first, but every time the vicar said "The life of Brian..." they'd think of Monty Python hilarity and the giggles got worse and worse, until they couldn't help laughing. What seemed to make it even funnier was the vicar hadn't realised the connection and was delivering it in a very serious manner, made them howl even more for some reason.
They managed to mask it behind handkerchiefs, some friends and relatives even commenting on the fact they must have been really close to have cried so much in church. There was also much hilarity later when discussing it with other relatives who knew about Monty Python, turned out some others had to stifle their laughter in the church service too.
Also, mil died last year and dh organised the order of service etc. bil proofread it etc. and he was doing a reading and prayer at the end. Even though he'd helped sort out the order of service bil hadn't realised he was doing the prayer! Cue he realised a couple of minutes beforehand and panicked a bit, we who knew found this funny for some reason and had to stifle our giggles. Fil did also find it funny when told later!