BBC英语口语:来参加我们的派对吧

VICKI:Let's have a BBC Learning English party!

MATT:Yeah, why don't you come over and join in?

VICKI:Even if you can't come over here, you can still join in with our party!

MATT:Oooooh I like this song Vicki – come on – let's dance!

VICKI:This is a great song to dance to. And the lyrics even say 'get down' which means to dance.

MATT:Yeah it's quite informal and you hear it a lot in songs, especially in American English. Hey - look at Paul, he's really getting down.

Come over (to…): 短暂造访,顺便来访,来
If you have nothing to do this evening, come over and have dinner with us.
如果你今天晚上没事，到我们这里来吃晚饭吧。

Join in (with sb/sth): 参加,加入(活动)
she listens but she never joins in.
她只是听,但从来不发表意见.