muck around
https://gyazo.com/c437620514b1e2700e30c7d75343768d
source: ชุมชน Steam :: :: Danshi Koukousei no Nichijou
muck around = muck about
British informal behave in a silly or aimless way, especially by wasting time when serious activity is expected:
ふざける, ばかなまねをする
e.g. he spent his summers mucking about in boats.
(muck about with/muck around with) spoil (something) by interfering with it:
【物を】いじくり回す «with»
e.g. they did not want designers mucking about with their newspapers.
#phrasal_verb