He/She clearly looked different from usual so I knew he/she hadn't just been drinking beer.
He/She clearly wasn't being his/her normal self so I knew it wasn't just beer.
He/She was staggering about and picking fights with everyone.
友人やパートナーが性格が非常に変わるまで飲むと大変ですよね。
明らかに = clearly
いつもと様子が違う = looked different from usual ; wasn't being his/her normal self (文字通り=「いつもの自分と違う」という表現です)
もうフラッフラ 異常に絡んでくるし=>
He/She was staggering about and picking fights with everyone.
quarrel; pick fights = 絡む