In my opinion "Friends" lost steam in season seven. The originality was gone, several plotlines had been seen before, the jokes were not as good and the characters had become stereotype versions of themselves. And when they couldn't come up with anything better they resolted to sex jokes.
As is the case with this episode. The baby's cake was supposed to be shaped as a bunny but turned out shaped like a penis. Lame sex jokes follow. Sex jokes can be funny if they are clever, but when sit coms use it it nearly always means one thing - they couldn't do better. Because it is really easy to make sex jokes and have people laugh. It's one of the easiest ways there is. Really, it doesn't take much effort, I know this from my own writing experiences. Resolting to sex jokes is something that's generally drawn from necessity, no good jokes came to the writers so they went with sex. I used to expect more than that from a show like "Friends".
The only thing I found entertaining in this episode was the video for Emma. It was funny to see what the Friends recorded and it would be interesting to see Emma's reaction to seeing it in the future. But the rest of the episode went by unnoticed.