This is the perfect way to get back at your teammate!
The other day, Alli decided to share a video of Dier dancing in the Spurs changing rooms and let's just say that his dance moves really didn't impress us.
And as you can imagine, football fans across the country had a right good laugh at the defender-come-midfielder.
The thing is, Alli probably should have thought twice about this, because, over the past few months, there have been loads of pictures and videos of the young midfielder popping up on social media.
And that obviously didn't go unnoticed by Dier who well and truly shut his teammate up with one of those videos from Alli's past.
Just have a look at this...
Yep, that is apparently Alli singing Sandi Thom's 2006 belter 'I wish I was a Punk Rocker'! Seriously, if this is him, then this might just be the greatest video of a footballer before they were famous we have ever seen.
We reckon Alli might be on the hunt to find some funny videos of Dier, so if you know of any then be sure to send some his way!