Marnie: I fight my fella over my knix!

UNDIES ANGER: Marnie bickers with Casey REALITY TV beauty Marnie Simpson has revealed she and her boyfriend Casey Johnson are always arguing – because she NEVER wears knickers.

The former Geordie Shore star confessed she loves going commando and her choice to go bare often ends in a slanging match with Casey, 22.

Loved-up showbiz couple Marnie, 26, and Casey met while filming MTV show Single AF last year but split up in August.

However, MTV came to the rescue once again and sent them both to appear on Ex on the Beach in a bid to get them back together.

They rekindled their romance, but the hot duo still bicker over Marnie’s commando habit.

When asked if they ever argue, Marnie said: “All the time – then the next minute we’re best friends again!

“We had an argument in the car on the way here because I’m not wearing underwear – but I’m wearing a jumpsuit!”

Casey added: “In my defence, she never wears knickers anywhere! We argue about petty things.”

In the trailer for the eighth series of the fiery MTV show, Marnie is seen confessing to giving a fella the “best night of his life”.

And it seems she’s very confident when it comes to her bedroom skills as she’s previously described herself as a “10 out of 10”.

Ex on the Beach starts next Tuesday on MTV at 10pm.