Personal rivalries can come about in many different ways - sometimes they're friendly but other times we're not.
#1.James Haskell & Neil Back
Haskell was caught in an online row with World Cup-winner, Neil Back. The spat began when Hask retweeted an official post from the England Rugby account, in which Haskell calls upon the Manchester crowd to get behind the team after they had already been knocked out of the Rugby World Cup.
They're certainly not on each others Christmas card list.
The Wasps captain quickly hit back at the former Leicester flanker's slight...
#2. Marcus Smith & Louis Rees-Zammit
The Wales winger has claimed England fly-half Marcus Smith "chats so much s**t" on the pitch.
Zammit revealed the England playmaker is someone who wind him up on the pitch, saying: "Marcus Smith, I remember the last time I played against him, he proper went in for me.
"He shoved my head in the ground. He was doing all sorts to me. I kind of laughed at it and carried on with my game."
He laughed: "Marcus Smith chats so much s**t on the pitch. It’s unbelievable. Then he comes off the field and he’s a legend. It’s weird. It's a good little rivalry."
#3. Alun Wyn Jones & Kyle Sinckler
Despite clashing on more than one occasion for club and country, the pair are actually good friends. Sometimes, friendship, can fuel a rivalry just as much as hate.
Jones wrote in his recent book: "Kyle Sinckler is good fun, a connection between us in Adam Jones, the tight-head ahead of me for so long for Ospreys and Wales for so long, a coach for him in his formative years was a good icebreaker.
"I'd like to think we get on. I like his aggression and energy on the pitch. Those are assets that can be harnessed, not controlled.
"We've clashed a few times on the field but it's all good fun."
#4. Andy Goode & Dave Ward
Andy Goode has gone on record about how much he doesn’t like Dave Ward.
It all kicked off when Goode called Ward out on Twitter for allegedly spitting on Wasps hooker Thomas Young and stamping on his leg. Goode called him ‘an absolute coward’ and Tweeted photos of the incident.
#5. Brett Ferres & Craig Huby
Rugby league ace Brett Ferres was filmed bedding the wife of his club team-mate and best man by his own missus. Devastated Amanda Ferres, 29, is said to have walked in on him and Victoria Huby, 30, who is married to his Super League pal Craig Huby.
A source said Amanda caught them on camcorder last week and sent the footage to Craig, 29. I doubt they'll be out having a pint anytime soon. It's fair to say any meetings they had on the field after that were tasty.