Is furious about grandma getting regularly barged around in horseplay (11)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Is furious about grandma getting regularly barged around in horseplay [NAN (=grandma) + DGA (“regularly” means alternate letters of <b> A <r> G <e> D only; “around” indicates reversal) in FUMES (=is furious)